lusus naturae [loo-suhs-nuh-tyoo-ree]
1. freak, monster, or mutant.
EX. "Lusus naturae," Red mumbled into her helmet as she reloaded her rifle, "Demons of the flesh. Things are worse than you feared. This things been to a million planets. It could already be any member of the crew. Be sure to watch Clark. Now, Gran, I'm gonna need you to watch my back. Gran?"