An arboreal critter is an animal that lives in trees. The crossword solutions for this term are ORANG (5 letters), APE (3 letters), Titi (4 letters), LEMUR (5 letters) and TOAD (4 letters). ORANG is a species of great APE native to Indonesia and Malaysia, while APE is a common name for any primate that is not a human, monkey or prosimian. Titi is a type of small monkey found in South America, LEMUR is a type of primate native to Madagascar, and TOAD is a type of amphibian.