These live in dark places. Their PoisonBarb is quite venomous.
Final Fantasy VI PlayStation Bestiary entry
The Cartagra (or Trilobiter in the SNES version) is an enemy in Final Fantasy VI.
Stats
Battle
It has inherent protect status and can 
Poison characters. Due to protect, physical attacks will be ineffective, so the player should use Celes's Blizzard spell to defeat them. Antidotes can be stolen from it to cure the poison.
Formations
| Number | Enemies | Encounter flags | Introduction flag | Musical theme | Magic AP | |||
|---|---|---|---|---|---|---|---|---|
| Normal | Back | Surrounded | Side | |||||
| 375 | Cartagra, Acrophies x2 | Sides, individual | Battle | 0 | ||||
| 377 | Cartagra x3 | Sides, individual | Battle | 0 | ||||
AI script
Attack Turns:
1st Turn: Attack (66%) or Poison Barb (33%)
2nd Turn: Attack (66%) or Nothing (33%)
3rd Turn: Attack (66%) or Nothing (33%)
Etymology
The Pseudomonarchia Daemonum, Thomas Rudd's variant of the Ars Goetia, and the Dictionnaire Infernal go into more detail, with Gamigin forcing the souls of those who drowned into "airy bodies" to answer questions in either, with Weyer and de Plancy further claiming that Gamigin can do likewise for souls "which dwell in purgatorie (which is called Cartagra, that is, affliction of soules)".