Man-faced Ape

Man-Faced Monkeys are a race of carnivorous primates capable of disguising themselves as humans and are capable of mimicking human speech. They reside in Numere Wetlands. They use their deceiving appearance and abilities to lure unsuspecting humans into the foggy wetlands and when their guard is down the Man-Faced Ape and other animals attack and will proceed to devour the humans as they love the taste of fresh human flesh. They must resort to this sneaky tactic due to their lack of strong bodies and are quite weak and must resort to attacks in large numbers when their prey's guard is down.

Trivia
In the manga Hisoka kills both Man-faced Apes, while in the 2011 anime he only kills one of them.