I think you are over using spoilers, but if that is just your style, then go for it I guess.

Chaos Butterflies are capable of rough alterations to the shape of the swarm, which, combined with their Disguise Self Spell-Like Ability, allows them to attempt to disguise themselves as virtually anything imaginable.
This needs the crunch to back it up, since right now they can disguise themselves as any sort of a swarm of fine outsiders.