Mario theme one shot. How to make Bowser

[CMagnum]

I am dming a one shot adventure for a few friends and came up with the idea to have them play in a Mario world setting. I will use mushroom and turtle themed bad guys for the most part, have bricks with mushrooms that enlarge person and leafs which grant limited flight, green pipes, lava pits and balls on chains with limited range and bite attacks.
I was wondering what you would suggest to use as a template for Bowser?
They will be playing level 5 characters. I guess a breath weapon and a tough melee stomp attack would be useful. Any ideas would be a great help thanks.

[Millstone85]

I remember joking in the "Let's Read the MM" thread (kind of dead now) that the dragon turtle probably has a tortoise version that kidnaps myconid sovereigns and take control of their colonies. The duergar would be particularly good at dealing with such situations, with their Enlarge ability.

Doesn't work for your math, though.

[tmjr6]

Dragonborn or Half-Dragon Battlerager Barbarian?

[90sMusic]

I'd make him a young red dragon.
18 AC seems good, high for level 5 characters.
178 hitpoints sounds good for a single enemy.
Immunity to fire, I might tone down to just resistance to fire since Bowser is frequently defeated by being thrown into lava...
For the multiattack, i'd leave the 2 claws but take away the bite as it seems excessive.
Then scale back his fire breath weapon to maybe 6d6.

His size and ability scores are good I think.

Think that would make a pretty decent bowser who would be a strong, but beatable, boss encounter.

[EvilAnagram]

I'd make him a young red dragon.
18 AC seems good, high for level 5 characters.
178 hitpoints sounds good for a single enemy.
Immunity to fire, I might tone down to just resistance to fire since Bowser is frequently defeated by being thrown into lava...
For the multiattack, i'd leave the 2 claws but take away the bite as it seems excessive.
Then scale back his fire breath weapon to maybe 6d6.

His size and ability scores are good I think.

Think that would make a pretty decent bowser who would be a strong, but beatable, boss encounter.

This is solid, but should we stat out his flying clown-faced machine?

[MadBear]

This is solid, but should we stat out his flying clown-faced machine?

Well if the dragon already has flight, maybe you just add in an optional rule that:

"When bowser drops to 100 hps, his flying machine breaks and he loses his ability to fly."

that might be too simple, but seems like a good way to add it in without adding much too the red dragon template.

[SociopathFriend]

Depends how you want the Bowser. Raid-boss or leader of legions and so on. Plus your group and how many of them there are and so on.

(Edit: wow I took longer than I thought- this was an empty thread when I started)
However, if I were to consider him only a single-boss I would go with this- I'm just going off the top of my head here so this presumably requires tinkering. My DMs favor hard and zany bosses so this might be a bit off for that reason as well- I may have overnerfed certain parts to compensate.


HP: 12d12 + 84
AC: 19
Size: Huge
Type: Dragon/Demon (Up to you)
Movement speed: 30 feet

Basic stuff- I guessed about the health


Str: 25
Dex: 10
Con: 25
Int: 16
Wis: 13
Cha: 16

Based off of adult dragon stats though tinkered with


Actions:
Multiattack-
Bowser can make two attacks: one with his bite and one with his claw.

Claw -
Melee Weapon Attack: +13 to hit, reach 5 ft., one target. Hit: 14 (2d6 + 7) slashing damage, can grapple as a bonus action if it hits.

Bite -
Melee Weapon Attack: +13 to hit, reach 5 ft., one target. Hit: 18 (2d10 + 7) piercing damage plus 7 (2d6) fire damage.

Flame Breath - (4, 5, 6 recharge)
Bowser exhales fire in a 30-foot cone. Each creature in that area must make a DC 18 Dexterity saving throw, taking (12d6) fire damage on a failed save, or half as much damage on a successful one.

Again, a somewhat weaker Adult Red Dragon, but I think the special abilities is where you want him to shine anyways.


Special Actions (as a bonus action, Bowser can make one normal attack of the above kinds after using one of these):
Shell Shift -
Bowser slips into his shell and moves in a straight line up to 60 feet, damaging all creatures he encounters during this movement with 4d10 + 7 bludgeoning damage and 2d6 + 3 piercing damage. Large and smaller enemies must succeed on a DC18 Strength saving throw or be knocked prone. A Dexterity save of the same value will half the damage and not be knocked prone. Bowser will not take damage while within his shell and will pop out of it at the end of his turn.

Koopa Kall -
Bowser summons 1 + 1d6 Koopa minions to enter the hall.

Bob-Omb -
Bowser throws a Bob-Omb to a targeted area within 45 feet. If a creature is within 5 feet of the landing Bob-Omb it will explode in a 30 foot AoE that deals 5d8 bludgeoning damage (counts as magical in terms of damage reduction). If the Bob-Omb does not land within 5 feet it will remain there for 3 rounds before exploding at the start of Bowser's 3rd turn after throwing it. Any other Bob-Omb caught in the AoE will explode as well. A DC15 Dexterity save will prevent all damage from a single Bob-Omb. Players can pick up the Bob-Omb during the 3 rounds of it not detonating, though it cannot be disarmed. If any fire damage is dealt to a Bob-Omb it will explode.



The Shell Shift is a unique method for Bowser to get around and re-position as he cannot be stopped from doing so via traditional methods. The King of the Koopas isn't afraid of not fighting fair after all. The Bob-Ombs are intended to bring about a minigame of either Bowser himself setting up for a chain reaction or for the players to gather them and use them against him.
I wanted to work in his slamming move from Smash Bros but the Shell Shift kinda steals all of the mechanical value the move would have.



Traits:
Legendary Koopa Resistance -
Bowser is famously difficult to slay, he is proficient with all saving throws and has advantage on any that attempt to immobilize him such as grapples, hold monster, and caltrops.

Fire Immunity -
Bowser is thoroughly impervious to flame- not even being dunked in lava will harm him.

Koopa King -
As the famous leader- all Koopa-related monsters gain +1 to hit enemies when Bowser is within 100 feet of them.

Koopa Shell -
Bowser takes reduced damage of every type whenever he is attacked from any angle that is behind him. You also cannot flank from these angles.

Basically stuff that isn't attacks but I still think make Bowser 'Bowser'. He's hard to kill, dropping him in lava doesn't always work, he's the king of an entire kingdom (moral boost?) and he's a giant turtle with a spiked shell.

[90sMusic]

This is solid, but should we stat out his flying clown-faced machine?

Hah, whoops, forgot to mention remove his flying speed.

While it is true bowser does have a flying machine, I don't think I would include that as part of the encounter because any melee combatants wouldn't be able to do anything to him for half the encounter, which isn't very fun.

I might let him fly over the party at some point in his flying machine to threaten/insult/whatever them, but when the actual fight happens, i'd make it on the ground.

If you wanna go all out, you could make it a non-standard fight where the goal isn't really to kill him yourself, but to use other things around to hurt him. For instance, if he spawns bob-ombs as an action or lair action, you throw them at him or position them near him so he takes the damage from them. Do something like when something gets near them, it triggers their fuse, then they detonate instantly when it becomes their turn, but in the interim you could throw one at him, maybe give them disadvantage to athletics checks or simply make it an auto-success. Maybe hint to your plays they're small and look easy to throw or something.

You could do the original mario thing where the run up to fight him is more or less a straight path and he's hurling firebolts at random people on your run up, etc.

[MagneticKitty]

Will Bowser be a PC or an npc ? I know he's teamed with the Bros for a friendly game of tennis. And also for the rpg games

[MadBear]

Hah, whoops, forgot to mention remove his flying speed.

While it is true bowser does have a flying machine, I don't think I would include that as part of the encounter because any melee combatants wouldn't be able to do anything to him for half the encounter, which isn't very fun.

I might let him fly over the party at some point in his flying machine to threaten/insult/whatever them, but when the actual fight happens, i'd make it on the ground.

If you wanna go all out, you could make it a non-standard fight where the goal isn't really to kill him yourself, but to use other things around to hurt him. For instance, if he spawns bob-ombs as an action or lair action, you throw them at him or position them near him so he takes the damage from them. Do something like when something gets near them, it triggers their fuse, then they detonate instantly when it becomes their turn, but in the interim you could throw one at him, maybe give them disadvantage to athletics checks or simply make it an auto-success. Maybe hint to your plays they're small and look easy to throw or something.

You could do the original mario thing where the run up to fight him is more or less a straight path and he's hurling firebolts at random people on your run up, etc.

I love this idea. Heck, even if you wanted to just normally wack him to death, give him the property: Unless hit by one of his spawing bob-ombs this turn Bowswer is immune to all B/S/P damage and resistant to all magical damage.

that way, the melee characters would be really incentivize to use the terrain while the magic users do little to no damage until they figure it out.

[CountWolfgang]

I'm not sure if someone said this yet, but Dragon Turtle.

[Finback]

Put a half-red dragon template onto an ogre or giant. Drop the flight and boost the AC a little perhaps, but keep the firebreathing. Also, the giant-aspect then allows for throwing boulders, reskinned as koopa shells.

[CMagnum]

Thanks a lot for all your effort everyone! I took pieces of a lot of different advice here and did some googling and ended up with a pretty cool endboss that was tough but manageable for the party. I'm at work now but can put up what I ended up with if people are interested in a day or two when I get some free time 😀