Hilda

, full name, is a Demon that serves as Beelzebub IV's maid. She is also one of the main protagonist of the series.

Appearance
Hilda is an attractive blonde woman with green eyes and a well endowed bust. Her clothes are mostly black with white quillings and thus resemble Lolita Fashion. She is seen outside this outfit on usual occasions. One occasion being right after she wakes up, wearing a modest pink, night gown with her hair down. Another being when she infiltrates Oga's current school, dressing in the Saint Ishiyama High's uniform, though she complains that the shirt is "a little tight."

Personality
Hilda commonly displays a cold and impassive demeanor, a character trait that she breaks only on rare occasions. (excluding her interactions with Be'el). Toward Be'el she is very affectionate and protective, acting as the role of the mother and preforming the task a mother would such as cooking for and washing Be'el. She often knows more about the current situation than any of the other protagonists and is easily able to manipulate the others into doing what she sees best.

She is shown to be just as bloodthirsty and violent as Oga, a trait that earned her the nickname "Oga's Bride" at Ishiyama. In a fight she displays a complete confidence in her own skill and power, regarding her opponents calmly and often taunting them in mid battle.

She enjoys teasing and tormenting Oga, frequently making marks about his intelligence and (in her own mind) poor parenting skills. In the beginning of the series she is openly dissaproving of Oga as Be'els' parent but after the delinquent defeats Toujou she becomes much more accepting and warmer towards him, even thanking him after. But she still bickers with him.

In Chapter 104, it is hinted that her time with Oga and Baby Beel has changed her, as Isabella noted that her personality has changed since coming to human world and wonders what kind of human is responsible for this change.

Plot
Hilda originally came to the human world by command of the Demon King to raise his son, Kaiser de Emperana Beelzebub IV, to be a 'good' human destroyer. Beelzebub however got so attached to Oga Tatsumi, that she now observes him and his progress in being the future demon king's parent.

Power
Her main weapon is a swordstick-like umbrella, again fitting her victorian era theme. However she rarely draws the sword, especially against weak opponents she refuses to do so.

As a fighter she is quite skilled. Her skills gained her the nickname "Oga's Bride" at Ishiyama, as she dispatches her enemies in a similar manner to Oga (shoving her opponents' heads into walls).

In chapter 104-105, it is shown that Hilda is far more stronger than what she have shown before. She took down En's three wet nurses easily in a blink of an eye, as commented by Furuichi. And she also shove Hecatos up, through multiple number of floors in Himekawa's building with ease. But before she could show more of her strength, Oga took the center stage and asked Hilda to stand down. So it is conceivable that Hilda's real strength is still not shown.

It is possible that currently she's the strongest female character in the series.

Conveyance
Despite the fact that she is naturally just as fast as strong she is as a demon, Hilda rides a giant bird-like being named Ak-Baba.

Tatsumi Oga
One of the most complex relationships of the series, he and Hilda share a love-hate relationship, most often bordering on the hate side. Hilda often looks down on him and never hesitates to mock him. In turn, he finds her cold and manipulative personality annoying. However, it is shown on rare occasions that they do care about each other, such as when Hilda thanks him for helping her get Beel back from Toujou and when Oga became enraged at Hectatos for harming her. It's quite concievable, though, that maybe they feel something more for each other.

It should be noted that the two work extremely well together in a fight.

The other wet nurses have pointed out that being around Oga has changed Hilda. Hilda was also legitimately worried about Oga when he and Beel used a full synchro.

Beelzebub
Be'el is very close with his wet nurse, Hilda. She was given the responsibility as the mother by the demon lord which she takes seriously, even saying that she was only born to serve her master. For example is when she was stabbed, she still thinks of baby Be'el, not even minding that she has a hole in her stomach. She cares for him like a real mother and only shows her affectionate and loving side to him.

Her feelings for him have grown far beyond the resposiblity to watch over him and is shown to deeply care for his well being, becoming infuriated at her lack of ability to protect him when attacked.

Quotes
"Please Die." (Referring to Oga) 

"Mas...ter... Please... get a... way... " (Referring to Beel when she got stabbed by Hecatos)

"The one who can barely think straight because of this anger, because her master was put in danger...is me." (Referring to En's three wet nurses)

"You make me sick, thinking that you're wet maids like me." (Referring to En's three wet nurses)

Trivia
- In episode seven of the beelzebub anime, Hilda is shown to be a fan of soap opera

- It is hinted that she is more than 100 years old, since it is told by Yolda that the last time they met was over 100 years.