Here are some pictures of traditional chinese heavenly-beings/demons/hell-beings. Note that not all of them are ‘evil’. Some are of governors of hell.
Bi Xie (辟邪)- Evil Deflector
Qi Lang (七郎)
Qi Lang was one of the generals (the no. 7) in the General Yang family . According to folklore, he was trying to save his brother when Pan Renmei took a revenge on him by poisoning him in his drinks and later tied him onto a tree and shot him to death. Legend had it that after his death, he became the governor of all the innocent and wandering spirits between the hell and earth.
Niu Tou (牛头) – OX Head
Ox-Head (牛头) and Horse-Face (马面) are two fearsome guardians of Underworld in Chinese mythology, where the dead face judgement (and punishment) prior to reincarnation. As indicated by their names, one has the head of an ox, and the other has the head of horse. They are the first people a dead soul meets upon arriving in the Underworld; in many stories they directly escort the newly dead to the Underworld (apparently some try to run away). Usually, the two are mentioned together (牛头马面).