It revolves around a small eccentric blue monster named Bunsen who begins attending a middle school that previously only admitted humans.

In spite of prejudice against beasts, Bunsen befriends a human boy named Mikey Munroe and his homeschooled companion, Darcy.

[1] He originally considered writing a picture book featuring the characters, but decided against going forward with the idea until an executive from Nickelodeon saw the drawing and encouraged him to develop the concept into a television program.

Bunsen Is a Beast was Hartman's fourth and final animated series produced for Nickelodeon before his departure with the network, after The Fairly OddParents (2001–2017), Danny Phantom (2004–2007), and T.U.F.F.

Mikey Munroe, his human friend, helps him navigate through school, as he feels the pressure to prove that monsters can coexist peacefully without eating and harming others.

According to an article published in Variety, he kept the drawing in his office at Nickelodeon until a network executive noticed it and asked him to pitch the concept as a television show.

[4] When asked in an interview with Heidi MacDonald's Comics Beat if the show could be interpreted as a metaphor for "accepting and befriending refugees," Hartman mentioned that the social commentary was "a little bit" intentional.

Bunsen is excited to take Mikey to Dimmsdale to meet Cosmo on Friend-iversary, but trouble arises when Amanda secretly follows them and teams up with Mr. Crocker.

Mikey and Bunsen try to help local ice cream delivery guy Commander Cone find his dream job.