An ahool is a startling creature, resembling a chimpanzee with a pair of bat-like wings. These strange primates, with a 10-foot wingspan, are named for their distinctive call, which echoes through the nights of the jungle. Encounters with these nocturnal creatures are rare and rarely end without injury of either party. Nocturnal Howler. Male ahools are solitary, leaving the social females to raise the offspring in troops.