Raglayim tanninim are a possible inhabitant of a strange-larva-hellish seal. They are primarily notable for their high physical damage output and ability to drain a large amount of constitution. Note that raglayim constitution-drain is not caused by poison, so poison resistance is of no use.
"It's too big" madness
The character is occasionally overwhelmed by the sheer size of the raglayim. On rounds when it's too big, the character is unable to cast spells, play music, use spirit powers, or speak.
Tannin (plural tanninim) is an ancient Hebrew word meaning "sea monster" (or sometimes "serpent," and sometimes translated as "dragon"). Ancient Semitic religions used sea monsters to symbolize primordial chaos, and sometimes evil (see also Tiamat/the Chromatic Dragon.
Raglayim is a Hebrew word meaning "feet." It is a reference to a description of a centipede, marbeh raglayim ("many feet").