Beelzebub

Kaiser De Emperana Beelzebub IV (カイゼル・デ・エンペラーナ・ベルゼバブ4世)

Beelzebub IV (ベルゼバブ4世, Beruzebabu Yonsei) is an infant demon lord, and the son of the Great Demon Lord.
His full name is Kaiser de Emperana Beelzebub IV (カイゼル•デ・エンペラーナ•ベルゼバブ4世, Kaizaru de Enperāna Beruzebabu Yonsei).
This is sometimes further abbreviated to:

• Beelze-sama (Lord Beelze) is a term used by Alaindelon.
• Baby Beel (ベル坊, Berubō). The suffix "-bo" indicates a baby. The "Beel" syllable is pronounced with a short 'e', not a long 'e' as English readers may infer from the double vowel. 

Beelzebub is a baby with an abnormally wide build and green hair. Beel is almost always shown with his binky, save when he is being fed. Usually, he is seen nude (even in public), causing ordinary people to talk about him and his "parent" Tatsumi Oga. Partially due to Hilda's misdirection, the rest of the Oga's family believes that Beelzebub is Tatsumi's biological son, using their similar eyes (usually frozen in either a blank stare or an intimidating glare)
Baby Be'el is very easily impressed, especially by strong people since he himself is still weak and loses 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. It is also shown that he is afraid of insects. He often displays a fondness

Added by HelloImMeXD

for things that might frighten "normal" babies, such as violence, exposed muscle tissue (on an anatomy model), heavy metal music, and demonic toys.At the start of the series, Baby Be'el used to be a crybaby who used to cry and shock Oga all the time, but as the series goes on he gradually becomes braver to a point where he is now rarely seen crying at all. This is due to Oga's continuous teachings about what it is to be a man and a Demon Lord.