Monster Analysis: Magma Bulette

Thanks to @KageSatsuki for this art piece!

  • First Appearance: 107 Scaldseat
  • Armor Class 18-20 (MM 17)
    • Baby Armor Class ≤<=18
  • Speed 40 ft, 40 ft burrowing
  • Darkvision 60 ft, Tremorsense 60 ft, Passive 16
  • Immune to fire damage (untested)
  • Suggested Average, Max HP: 94, 135
    • Momma: 337 damage taken, 37 HDYWTDT by Grog
    • Baby 1: 98 damage taken, 39 killing blow by Planetar!Scanlan
    • Baby 2: 97 damage taken, 38 point killing blow by Platetar!Scanlan

The party first encountered a standard bulette in the Underdark waaaaay back in episode 4. These unaligned monstrosities burrow through dirt and solid rock, sensing any nearby movement with their tremorsense. They couldn’t care less what the living being is that’s in front of them; if there’s a creature around, the bulette wants to eat it, and will ambush it by bursting out of the ground.

Like their non-elemental cousins, the magma bulettes didn’t need a running start to jump up to 30 feet across (or 15 feet vertically), as one of the babies showed off in a deadly leap attack against Vax’ildan. Had Vax failed his dexterity save, he would have been knocked prone in addition to taking damage.


Unlike the standard Underdark variant, however, the bulettes of Scaldseat were elementally infused with fire and magma, to the point that even standing near one (living or dead) burned (not dissimilar to the elementally infused ember roc previously encountered). The saliva dripping from their toothy mouths (not maws) was laden with fire, dealing an impressive amount of piercing and fire damage on a successful bite (+13 to hit from Momma).

Additionally, Momma Magma Bulette’s description led us to believe that she was much larger than the one in the Duergar Warcamp. This size came with the added ability to swallow a target that she bit with an attack roll of natural 18-20 (which was bad news for Grog, who was already no stranger to finding himself in the stomach of an enemy). This was faster than the the Feymire Crocodile and the Kraken, who both had to grapple their prey before swallowing it. Like the kraken, the bulette’s stomach needed to take a certain amount of damage to be forced to make a constitution save to retain its contents (50 and 40 damage respectively, 25 DC Constitution Saving Throw for both).

Clever Girl

Upon the elemental monstrosities' appearance, Vox Machina attempted to get away with "Jurassic Park rules" by standing still and hoping they would burrow away. (Grog’s stealth roll of 16 WITH Pass Without a Trace would have clued in a MM bulette to their presence. We’d guess that the magma bulettes were no different.) With the element of surprise gone, the party resigned themselves to combat. In the span of two rounds, even with enhanced fire damage and bite-and-swallow action, Vox Machina made short work of them.

Grog and Vax immediately set to work whittling away at the big one's health. The massive size of the magma bulettes made it nearly impossible for them to dodge Keyleth's Chain Lightning, which dealt each of them a staggering 59 damage (177 total) in a single attack. Vex's natural 20 on Momma dropped her health another 72 points, leaving Grog to finish her off. Scanlan's True Polymorph into a Planetar (Scanetar, if you will) allowed him to mop up the two baby bulettes with his divine greatsword. (The complete lack of damage both he and Percy took were welcome changes to the state they were left in by the Underdark bulette.)

This relatively easy battle provided little challenge to the party, a mere wrinkle added to the additional challenge of holding their breathes in a chamber devoid of oxygen en route to a forge of the gods that had fallen into disuse. Perhaps Vox Machina could consider them a mere warm-up (only some pun intended) to the challenge the Core Anvil would lay before them...