i like to think that the salmhofer twins look the most babyish out of the irregulars (except the neo babies themselves; they don't count, they're literal babies). baby fat, big round eyes. very baby. also very feral. their big eyes also make them much more unsettling when they're going full-on chaotic, which they know and make good use of them.

the lucifen twins were starting to mature, especially allen. they have eyes that are somewhere in between round and sharp, quite undecided at the time of their deaths but i think they would've had sharp eyes by the time they were adults.

amostia definitely has sharp eyes. they can look round, he still has a baby face, but his default mood makes him have sharp eyes most of the time. whenever he softens, his eyes get a bit rounder.