The Unnamed Bug Eyed Demon was a minor threat from the end the animated film, Devilman: The Birth.
A yellow skinned humanoid demon with large blue compound eyes, large sharp teeth and a proboscis like tounge, he had a large chunky tail in between his legs.
When Akira and Ryo are fleeing from Texsch and Gardalza they hide in a large hidden room in Ryo's home, inside the room Ryo was holding a Black Sabbath full of drunken dancers. Ryo starts to kill them so there would be enough blood for Akira to transform into Devilman. After his transformation he goes on a rampage and stats to kill the other demons who had transformed from the party goers starting with Welvath, the Bug Eyed Demon is seen being killed shortly after.