Beelzebub IV

, full name, and abbreviated to Be'el , is the Demon King. Beelzebub is the son of the Great Demon King.

Appearance
Beelzebub is a baby with an abnormally wide build and green hair. Sometimes, he wears a yellow pacifier. Usually, he is seen nude to his genitals, even to the public, causing ordinary people to chatter about him and his "parent" Tatsumi.

Personality
Baby Be'el is very easily impressed, especially by strong people since he himself is still weak and looses to other babies as well as to cats. On the other hand he is not the smartest one out there and tries to force his way through the most simple problems.

Plot
Beelzebub came to the human world inside of Alain Delon. He was practically drawn to Oga Tatsumi from the beginning and is usually seen clinging to his back. Oga in turn did and still does not want to keep him around since he only causes him problems with other strong people at his school. Thus they set out together to find a person stronger than Oga.

Electrocution
When Baby Be'el is caused to cry for one of various reasons, for example Oga being in danger, it fries everything in a certain range depending on how loud it cries. Generally the energy used is higher than that of a 12.000 Volt stun baton Himegawa of the Touhoushinki uses against Oga in chapter 9.

Pee
Once a year Baby Be'el relieves the blessed urine that contains holy demon power. It can't be stopped by simple means such as knoting or diapers and would be able to sink a whole town. This however was prevented by Oga and Hilda riding on Ak'Baba to the ocean.

Giant
In the Demon World, Beel was able to turn into a giant and defeat the monster of the land.

Hidden Potential
While training with Saotome Zenjuro, a radio was used that made a "shadow" of Be'el. This shadow supposedly embodies the potential of its subject, and, as it was able to easily strike Oga into a boulder and crush that boulder, Be'el is hinted to have a large amount of fighting potential.