This is a list of characters on the animated television series The Mighty B!.
Bessie Kajolica Higgenbottom is a 9¾-year-old, geeky, bespectacled "Honeybee Scout" characterized by her extreme hyperactivity and unshakably dedicated work-ethic. Ambitious, infuriatingly-persistent, and highly sociable, Bessie is determined to earn every badge in existence on the firm belief that achieving this goal will transform her into a superhero known as the Mighty Bee (and it was implied in one episode involving a meeting between Bessie and the founder of the Honeybee Scouts that this theory actually may be true), showing obsessive devotion to the scouting troop and any mission that she establishes for herself in attaining her goal. Pure-hearted and friendly, Bessie is oblivious to other people's dislike of her, blind to the bratty Portia Gibbons's exclusion and belittling of her regardless of the severity of her insults. In spite of this factor, Bessie displays extreme precociousness and intellect, constructing both a robot and an atom smasher for the upcoming Honeybee Science Fair and showing the business and negotiation skills of someone twice her age. Nonetheless, she shows vulnerability to her weak eyesight, unicorns, cute animals, and stereotypically-feminine interests such as sparkles and glitter. Bessie also has a lisp; this can be noticed whenever she says a sentence that has the letter S. Amy Poehler plays the voice of Bessie Higgenbottom.
Happy Walter Higgenbottom is Bessie's cherished pet dog adopted in the pilot episode as a scraggly stray hanging around near the community fisherman's wharf. Albeit Happy was originally reluctant to be so forcibly adopted and lived in resentment with his new owner, he gradually grew to further appreciate her, albeit he is depicted as something of a sly character with manipulative mannerisms. Although Happy is incapable of speech, he communicates through barking that can somehow be comprehended by fellow characters in the series, though the exact wording of Happy's conversations with other characters is not translated or understood by audiences. He is gifted with partial anthropomorphism, as he demonstrates capabilities of walking on two legs, driving, gambling, or interaction with human characters. It was revealed in one episode that Happy was somehow mysteriously separated from his biological mother at a young age and that Mother's Day formerly presented unhappy connotations for him, though after a dog named Rose claiming to be his mother was revealed as a deceptive impostor, he grew to appreciate his adoptive family with the Higgenbottoms further. Happy appears to have a shady background, as he was formerly trained by a secret agency as an undercover dog and was treasured as an agent, though later wound up leaving this past behind. It also has been revealed that he enjoys gambling in his spare time in a secret casino intended for canines. He is voiced by Dee Bradley Baker.