This animal looks like what happens when a Pixar animator has a bad dream. And it's on your back!
Luckily, someone in the comments under this Tweet clued us in. This is the Sunda flying lemur, although that seems like a strange name for a creature that doesn't fly and isn't a lemur. It's a species of colugo, gliding animals native to Southeast Asia. Colugos are distantly related to primates, but not to any other kind of animal. They are nocturnal, which may explain their adorably huge cartoon eyes. Flying lemurs live in trees and are fairly helpless on the ground. No wonder this little guy is holding on fast to this person's back! -via Everlasting Blort