Monster Analysis: Gibbering Chasm and Roper


  • First Appearance: 2-50 The Endless Burrows

  • Armor Class 20

  • Speed 10 ft., Climb 10 ft.

  • Darkvision 60 ft., Passive 16

  • Suggested, Max HP: 93, 143

  • 0 Damage Taken, Temporarily banished by Jester

In our last monster analysis of the roper, we admitted that our reaction to the roper was, and we quote, “NO. Eww. Gross! Gross gross gross.” Not only has that not changed, but was amplified upon discovery of the sources of the voices in the deep…

Gibbering Chasm

  • First Appearance: 2-68 Reflections

  • Armor Class Unknown (Mouther AC 9)

  • Speed Unknown (Mouther Speed 10 ft, Swim 10 ft)

  • Mouther: Darkvision 60 ft, Passive Perception 10

  • Suggested, Max HP (Mouther): 67, 99

  • 0 Damage Taken

The whispers below the bridge belonged to a gibbering chasm, a horrifying expansion of the gibbering mouther. These aberrations are heinous and, like ropers, driven by their ceaseless hunger. Gibbering mouthers are incredibly slow (and, in the case of the gibbering chasm, completely encased in the chasm in which it resides), but make up for it in their maddening abilities.

The Mighty Nein experienced its eponymous ability, gibbering, firsthand as they tried to cross the bridge. Every time any one of them made a noise, the voices rose up from below in a cacophony that forced wisdom saves each instance. Failure resulted in either stun, bloodlust against the nearest available target, or a mad dash into off the side to the aberration below Thankfully, Nott and Jester didn’t spend enough time in the chasm’s grasp to experience its blinding spittle, which does exactly what it sounds like. Had anyone dropped to zero hit points by being bitten by the chasm, they would have dissolved into the chasm and become another set of eyes and whispering mouths amongst it.

Jester well and truly saved the day on the bridge. First, Pass Without a Trace allowed the Mighty Nein to succeed on their stealth checks when a number of them would have definitely failed without it. Second, she thought quickly enough to banish the roper, like she did back when the Nein were traveling to Xhorhas, before it could do more damage to her grappled friends or move them beyond the support of the bridge. Third, she had the courage to leap off of the bridge into the gibbering chasm to rescue Nott with a Dimension Door. Three hurdles overcome, and the party is still all together for the next phase of these catacombs…