Agwel was a small, amorphous and highly sadistic demon from Go Nagai's Devilman series.
Agwel was a small slime-like demon who's only recognizable feature was a head with deeply sunken eyes, a mouth full of long razor sharp teeth and a pair of antenna. His skin is usually either blue or light green, though it was brown in the second Devilman OVA.
In the Devilman manga, Agwel's first appearance was early on when a young schoolgirl was walking to her home late one night when she slips. When she realizes that it was blood she slipped on, she crawls a little further only to find the decapitated head of a man and a strange mound just in front of her. The mound turns its head and reveals itself as Agwel, it then kills her.
Later, Agwel is summoned along with the water demon Ghelmer by the beautiful demon Sirene. Agwel was sent to kill the Makimura family sucking Kensaku and Kousako Makimura through the walls. Not long after he attacks Akira Fudo when he tries to break into the bathroom to save Miki. Akira beats Agwel back and he retreats but after recovering Miki, Agwel again attacks Akira, but Akira partially transforms into his Devilman frm and wraps his antennae around Agwel's neck, pulling his head off. As he dies, Agwel's last words are "I'll be waiting for you in Hell, Devilman!"
Agwel appears in a flashback of Akira's when he was thinking of the various demons he had encountered over the years.
Devilman VS Getter Robo
Agwel breifly returns in the cross over manga alongside Sirene and other demons when she joined with Lord Gor to kill Devilman and Getter Robo.