Monster Halloween Costumes – Bug Costumes – A Swarm of Flies! Be afraid. Be very afraid. The Fly Costume includes the top with wings, pants, mask, hand and the feet covers. This is an excellent costume for fun and scary events! With the iridescent colors on the costume and wings, this certainly has the look of a fly! This is a Poly-Foam Costume. The mask is pulled on over the head with an opening in the back closed by velcro.