Potto
The potto is potentially the cutest and fuzziest primate you’ve ever seen. It’s also definitely the primate with the weirdest defense mechanism. Pottos have an elongated vertebrae covered in sharp growths that almost pierce the skin on the back of their necks. These neck growths make the potto hard to swallow and protect it from being bitten in a typically vulnerable area. Plus when it’s threatened the potto can tuck its head and ram its sharp bony neck into the attacker. Cute, fuzzy, fierce AF!
Source: http://www.wild-facts.com/2011/wild-fact-448-the-shield-potto/