D&D Mario Monday: Whomp

D&D Mario Monday Whomp

Last weekend was my buddy’s bachelor party weekend. Each of us pitched in for the festivities in a different way. My sworn duty was to run a D&D 5e one-shot during the day.

Initially, I’d hoped to run the highly-regarded The Wild Sheep Chase. However, it turns out my buddy had not only played it, but DM’d it as well. With that option off the table, I decided that the best course of action was to write an entire one-shot based on Super Mario 64 with custom creatures and a mash-up of inside jokes and references to previous campaigns and real-life events.

Because, you know, that’s the most logical decision I could come to.

I think it went well. It’s been a while since any of us played in person so I underestimated how slow things can be. I wound up cutting about 50% of what I wrote and we still played for over 4 hours.

However, one piece of this absolute meme of a one-shot that I was proud of was my whomps! Since we’re due for a Monster Monday anyway, how about we check out one of my creatures for a change?

Let’s jump into Whomp’s Fortress and defeat some whomps to get that star to save Princess Peach!

An homage of the infamous opening letter of super mario 64 using my friend's D&D character. The letter reads: Hey man: Please come to the castle. Uh, I don't know what castle this is man. I guess the one in front of you? Anyway, I've baked a pizza for you. Uhh bye, Lactarius
I commissioned my friend Zeldaandfairies to do an homage to peach’s letter in the opening of SM64 using my buddy’s stoner/pizza delivery boy druid from our previous campaign. 10/10 would commission again check out her Twitch!

Whomp Lore

Appropriately, whomps made their debut in Super Mario 64. They were first showcased in the aptly named Whomp’s Fortress level where they served as lieutenants guarding King Whomp.

These enemies are giant, walking stone slabs with a huge face on the front of their bodies and a bandage over a crack on the back of their bodies. They’re simplistic enemies, but they bring a fun mechanic into play in a game that was all about pushing the boundaries of gaming at the time.

The whomp’s fighting style was to rush up to Mario and throw their whole weight on top of him. This powerful move makes them a dangerous foe, but they were also invulnerable aside from that one weak point on their back.

The key to defeating the whomp was to fake out their body slam attack so they’d hit the floor, exposing their weak point. Once they were prone Mario cold then jump on them and ground pound them to defeat them.

Whomp Stats and Abilities

Here’s the statblock I came up with:

the stone slab whomp from super mario 64

You can also download a PDF version of the whomp’s statblock right here!


Weighing in at 94 HP and 17 AC this large stone slab has a rock-solid defensive foundation. This foundation is further reinforced by a respectable spread of common saving throw abilities.

Its +5 Strength modifier gives the whomp some extra oomph to their punches too. They’re in a good spot offensively.

Really, the only portion of their statblock that falls short here is the 20 ft. of speed. While this played out fine in the small battlefields their encounters took place on, I could see this being a huge issue otherwise. I was going for a lumbering rock behemoth-type creature, which worked, but it’s definitely a weak spot.

Resistances, Immunities, Saves, and Skills

The only damage resistance or immunity they have is to poison which was modeled after the galeb duhr and earth elemental’s poison damage immunity. However, their unique trait gives them a boost in this department so the whomp is not without some extra protection!

The whomp is a slow creature, so I gave it a couple of condition immunities to prevent it from being further hindered by some movement prevention crowd control. Immunity to exhaustion is mostly for flavor.

I don’t know if darkvision and tremor sense are canon abilities for whomps, but I figured if earth elementals can have it so can they. In hindsight, the fact that you can just walk past these guys undetected in SM64 should’ve signaled to me that they’re not super gifted in the perception department…

I think CR 6 was a fair rating for the whomp. They’re overall quite solid, but with a few key weaknesses that make playing them and against them risky and rewarding.

Traits and Abilities

(Almost) Hard as a Rock was my solution to the whomp’s in-game mechanics. They’re nigh-invincible when hit head-on, but when Mario smacks their weak point on their back they’re as squishy as a goomba.

Ergo, when you hit the whomp from the front with a direct attack, the whomp is resistant to it. Conversely, if you hit it from behind with a direct attack, they’re vulnerable to it.

Saving throw-based attacks are the exception here. They skirt the whomp’s resistances, but in turn, these attacks can’t take advantage of the whomp’s potential vulnerabilities.

I thought it was a cool way to incorporate the vulnerability mechanic in a flavorful way. It doesn’t see a whole lot of use so I jumped at the chance to use it in a way that made sense.


The whomp has two unique offensive actions.

The first is a two-attack Multiattack which includes two punch attacks. This deals a total of 18 bludgeoning damage per round. It’s reliable, but it’s not particularly interesting.

The second is a high-risk, high-reward AoE slam attack modeled after the whomp’s signature move in Super Mario 64. The whomp topples over on top of a nearby creature. Everyone within 10 feet of the target needs to make a Dexterity saving throw to avoid taking an average of 18 bludgeoning damage and being knocked prone.

Obviously, this is a much more powerful attack than the whomp’s Multiattack option. However, there is a key downside to this maneuver. By toppling over, the whomp knocks itself prone, exposing its weak point for the party to take full advantage of for the next round.

So sure, Topple Over can deal some massive damage under the right circumstances. Yet this damage comes with a hefty price, just like in the games.

Whomp Strengths

High Potential Damage

Topple Over can output a ton of damage if the right conditions are met. If you can guarantee at least three enemies will be trapped in the area then it becomes a very enticing move. Not only does it deal a respectable amount of bludgeoning damage per target, but it also can knock them prone.

This means that any of the whomp’s melee attacker allies have an increased chance to hit said prone targets. Which in turn increases the damage output of all your creatures.

It’s a devastating move if things work out in your favor. If they don’t, it’s still a decent move since you’ll deal some guaranteed bludgeoning damage to any creature that passes the saving throw.

Solid Base Defenses

17 AC, 94 HP, and a solid array of ability scores make for an impressive defensive foundation for the whomp. Tack on a few condition immunities, immunity to poison damage, and resistance to direct attacks from frontal attacks and you have a real hardy creature.

These base defenses give them the ability to make risky decisions in combat. For instance, you can afford to take a few bad hits from behind after you topple over and deal some massive damage to half the party because you have that whopping 94 HP and 17 AC.

Whomp Weaknesses

Mediocre Movement

20 ft. of movement was a poor design choice. Like yeah, thematically they aren’t fast creatures, but I did them no favors by granting them below-average movement when positioning is a key element of their success in combat. Moreso than it usually is.

(Almost) Hard as a Rock requires you to constantly pivot and move around to prevent the party from getting free shots at the whomp’s back. This is much harder to accomplish when the entire party has between 5-10 ft. more movement than the whomp.

I think 20 ft. of movement could’ve still worked out fine if I gave them reach on their Punch attack. As-is it’s mediocre damage with a 5 ft. range. There’s not a whole lot of use for it outside of “it’d be a bad move to Topple Over at the moment, I might as well Multiattack”.

Poor Positioning is a Death Sentance

(Almost) Hard as a Rock is a cool mechanic in my super-biased opinion. It incentivizes teamwork and good positioning from the players as they need to constantly find ways to turn the whomp around and gain control of the battlefield to get behind it.

If they fail, then the whomp becomes even tankier, which means the fight will last longer, which in turn means that the party will take more damage and expend more resources to get past this obstacle.

However, if they succeed those strong foundational defenses don’t stand a chance against the double-damage attacks smashing into the backside of the whomp. You need to be on your toes when piloting a whomp. One slip-up can mean a ton of excess damage being given to the party on a silver platter.

How to Play a Whomp

The King of Small Spaces

A small battlefield gives the party fewer opportunities to spread out. This means that they’re more likely to be packed together and ripe for a high-value Topple Over.

Trapping the majority of the party in a devastating AoE, and potentially knocking them prone, and further limiting their movement is an enormous win for a whomp and its allies. Especially if their allies can take advantage of the prone party members and attack them at advantage with melee attacks.

A small battlefield also means that there’s less room to kite the slow-moving whomp around. Their poor movement speed is still an issue, but it’s a less noticeable one when your movement options are limited.

Give ’em a Distraction

When flying solo, the whomp’s positioning is the only tool it has to prevent the party from finding its weak point. However, if you add a couple of minions into the fray, the party can’t focus on the whomp’s weak spot without leaving themselves exposed to the whomp’s allies.

In a multi-creature encounter, the whomp turns into a disruptor-type tank. While Topple Over has some fantastic potential damage its ability to knock enemies prone should not go unnoticed.

Knocking a party member prone both hinders their movement and makes them susceptible to melee attacks until they’re able to stand up on their turn. It puts them in a vulnerable state, making them ripe for the picking for the whomp’s allies.

In this scenario, simply try to keep the party from hitting the whomp’s exposed weak point until your creatures are ready to rush in after a high-value Topple Over attempt. If all goes well, you could deal some devastating damage to the party!

The Whomp King

I could give you 5 plot hooks for this oddly-specific Mario enemy… or I could swerve in the other direction and showcase a boss creature I made using the whomp’s statblock.

One of the stars in Whomp’s Fortress is earned by defeating an enormous whomp named The Whomp King. So, concerning the source material, I felt that I should crank a whomp up to 11 and throw it at the party as the miniboss of the adventure.

Here’s what I came up with:

The majority of the statblock is unchanged aside from the numbers. Understandably The Whomp King is hardier and deadlier than your typical whomp. However, there are a few notable changes outside of its Legendary Actions.

The first is Legendary Resistance which I actually wound up not really needing, but there were 7 players so I wanted to give this big boy a chance against any potential CC locks.

The second is that I reworked how Topple Over works for the king since he’s a seasoned veteran at falling on top of things. Unlike a regular whomp, The Whomp King doesn’t stay prone after he topples over. Instead, the action has a recharge rate.

The third was that I gave him 30 ft. of movement which helped a bit.

I felt that this worked well because it removed a core weakness from the base creature for a high-stakes boss fight, but it kept things fair by ensuring that this powerful attack wasn’t spammable the entire fight.

The legendary actions gave him a bit of crowd control, some extra positioning opportunities, or a pinch of damage if the whomp king wished to capitalize on a nearby prone enemy.


Hopefully this breakdown of my own homebrew serves as a helpful outline for making homebrew creatures of your own. As you can see, my work is clearly not perfect, but it served its purpose and I got to try out some fun design bits during a low-stakes one-shot.

If I wanted to, I could always take my whomp as a foundation and put it through the wringer again to polish it up and use it again down the road.

The hardest part of homebrewing a creature is taking that first step and making a rough draft. The numbers, balance, and all the nitty-gritty mechanical stuff are important, but the fun lies in your unique vision and ideas.

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  1. I like this idea, but since D&D doesn’t distinguish between “backstabbing” and attacking a back or front side, this might need a bit more development or explanation. I guess with minis it wouldn’t be too hard, but otherwise it might be better to simplify it by saying they’re vulnerable to all damage when they’re prone. Does psychic damage come into that at all? 😀

    I personally would also just allow the whomp to do its Topple Over attack only if it starts its turn not prone, so it can’t do it every single turn, but it doesn’t necessarily need to Recharge either.

    Great idea in general though! I once did a Disney-themed one shot and it was a lot of fun in some of these same ways.

    1. James Griffith says:

      Ooh you know what that’s a fantastic idea. We played with minis so it wasn’t much of an issue but I like the consistency from your idea a lot more!