Nightmare Fuel The horrible scream by the main villain as his hand gets nipped off by a croc.
While discussing the death of Elaine's husband and asking if the authorities ever found the body, Joan says "Just the one... piece." Have fun guessing which piece they found. Possibly Fingore since they had to identify him somehow.
Zolo himself, period. An intelligent, brutal, cruel and sadistic psychopath with a private army at his beck and call, and one who will stop at nothing to get what he wants. No wonder Ira and Ralph, who are criminals themselves, are terrified of him.
Sequelitis: Maybe Diane Thomas would have been able to make a worthy sequel, but after her death we got a horrible mess that was obviously the result of mass studio interference. Rather than make a third film, the cast went and made The War of the Roses.