Capelets have big, adorable eyes that change color according to their moods, extremely long tails (see image) and fast little fingers with opposable thumbs. Their tails are not prehensile; though a tail curled around something indicates pleasure with that something. A limp, straight tail usually indicates poor health. Capelets can walk on all fours or switch to bipedal movement. Faint white whiskering details the skin of a bluish-gray face under a big white mane starting with a sort of mohawk crown. In rare cases, the face of a capelet may be black or white, indicating a telepathic troop leader (other capelets are not telepathic). White is far more rare than black. Their backs and upper tails are usually colors ranging from reddish-brown to black. The lower halves of their tails can range in color from white to brown to black and anywhere in between. Chests, underbellies, legs, and feet are usually white, though capelets under 10 years' age usually have somewhat black fingers.

They are monogamous and attentively loving, breeding once a year (if possible) and gestating for four months. Almost always, a capelet will give birth to non-identical twins which are weaned within two weeks. After that period, a mated pair will usually defer to the father taking care of the babies until they reach an independent age at 2 months. Once cared for by a human for more than a week, they become so attached that were the human to die, the capelet would probably die of heartbreak too. Capelets eat worms, insects, fruit, and love sweets such as sugared sap or soft pastries. In the wild, they will eat the gummy sap from trees.