This is a colugo. According to a Berkeley University article, this "'flying' lemur of Malaysia is the champion of all gliding mammals, able to drop from the forest canopy, glide more than the length of two football fields, execute 90-degree turns and then alight gently on a tree trunk."
Colugos were formed millions of years ago after a squirrel and a bat met at a tree-shrew party in college, decided they didn't give a damn about what society thought, and would stay in Malaysia forever to produce their race of flying squirrel bat children.*
*Not scientifically proven.