[Nicky91]

Squiggly Monster: i recognize that voice too, but my first guess hmmm idk who to mention now, i do think it's someone who finds himself attractive, i do btw know this one can sing, Michael Shannon

Broccoli: where Nicole said Bill Murray, i am more thinking of Dan Ackroyd or a James Belushi also older men, but we know they can sing, and that broccoli has some music background for sure not a singer as main profession but he has done some singing before

Mushroom: a very unique voice, Glee's Alex Newell comes to mind for me since he also got a quite high vocal range, but due to the mushroom appearance, almost similar to a big hat, and who loves his hats, and who can sing that high Boy George