Iris

Appearance
From her portrait, Beel's mother seems to be a pretty woman with long black hair and gentle facial expression. She has no visible demonic features.

Personality
Not much is known about her, but she is seen to be a very kind, caring and beautiful woman who treated Hilda like family and showed great compassion to her baby, Beel.

History
Little is known about her as of yet, other than that she was like an older sister to Hilda. Iris gave Hilda a necklace and asked her to take care of Beel if she was to ever pass away. The Great Demon King once painted a portrait of her, but out of embarrassment, he created an artificial demon to stop anyone from seeing it (despite it actually being quite good). Hilda mentioned that Beel probably doesn't remember her but according to the manga on chapter 168 page 19, Hilda mentioned that she would be pleased to have Beel meeting his mother one day. But when Oga asked Hilda whether lris is still alive, she remained in silence. The Great Demon Lord instructed Hilda to become Beel's "mother", implying no one else at the time was able to fulfill that role.

Plot
Iris's portrait, the "demon portrait", as it came to be known was requested by the Great Demon Lord to be retrieved by Hilda and her human companions. The painting itself was actually owned by Kugayama of St. Mark Academy, an acquaintance of Himekawa, who comments that the painting is of "a very pretty woman".

Hildegarde
Hilda used to serve Iris since before Beel was born. Iris always treated Hilda like family and gave her the necklace she is wearing in the painting before asking Hilda to take care of her baby.