I was thinking of ants being fiends. Why?
1.) They are kinda/very annoying sometimes.
2.) They take your unattended food.
3.) They make nests anywhere. Like in your garden or your flower pot.
4.) They will bite you. The bite itches so much.
5.) They'll eat your beloved pets to death. (Poor Chubby... got eaten by ants.)

Anyways, there are 3 kinds of spawn enemies.
1.) Dust Bunnies (Beasts)
2.) Glob Drops (Jellies)
3.) Grave Scarabs (Undead)

How about a fiend one?
If you think it's stupid, I don't really mind.