Bunsen

Bunsen is a one of main protagonist; a beast who is the first beast of a human school in real life. He is the best friend of Mikey, a human who helps him "fit in". He is the titular character of Bunsen Is a Beast.

Optimism
Bunsen has a very friendly, kind-hearted personality, though some find his boundless energy and optimism to be annoying, most notably Amanda Killman. He is also somewhat flighty and easily distracted, but always well-meaning, with a very strong moral center. Though he can be naïve, Bunsen is shown to be very witty and clever when he needs to be, and is capable of problem-solving on the spot and outsmarting his adversaries with little effort. Bunsen likes everyone he meets and always sees the good in people rather than the bad.

Bunsen is a wild spirit and tries to do anything and is striving to do anything as he wishes. He aspires to explore different worlds, try new things, and help people have fun and live free, often clashing against the tyrannical aspirations of Amanda Killman's evil reign. He and his best friend Mikey travel leisurely all throughout Muckledunk, often getting themselves into many exciting and dangerous situations.

Temper
Despite Bunsen's easy-going nature, there have been times where he has been pushed to his limits. For instance, in "Unhappy Campers", whenever the Beast of Muckledunk Blog posted an annoying blog about what he had for lunch, he would yell at him, She Carey the balloon In God Wishing"Nobody cares!" or "Get a life!"

Physical appearance
Bunsen is a blue monster, with a square shaped body. He has a blue head, a light blue stripe on his chest, a turquoise stripe on his stomach, and has white fur on his underparts. He also has a large pink mouth and an overbite. Bunsen has pink arms and legs. He has a tuff of hair on his head, which is the headspout he eats and sometimes drinks from. He has two short purple horns on his head which are prehensile, and large yellow eyes. He has a short blue tail with 3 purple spikes on it.

Mikey
Mikey is Bunsen's best friend. Bunsen has become very good friends with Mikey, and their relationship could possibly be seen as brotherly; as they always look out for each other and help each other out. Mikey is very loyal to Bunsen as Bunsen is to Mikey, and they can be seen hanging out with each other most of the time.

Amanda Killman
Bunsen and Amanda Killman first met in "Bunsen Is a Beast". Bunsen wouldn't exactly call Amanda a friend because she is always trying to get rid of him; despite that he is always tolerant towards her.

Beverly
The exact relationship between Bunsen and Beverly is currently unknown, as they rarely interact with each other.

Darcy
Bunsen and Darcy are good friends.

Miss Flap
Miss Flap is Bunsen's teacher. It's unknown of their relationship as of this point.

Cosmo Cosma
Cosmo and Bunsen met at a "Creature Con", a place where all magical creatures come to unite.

Commander Cone
In "Bunsen Screams for Ice Cream", Bunsen is attracted to the music and ice cream from Commander Cone's truck. After getting bribed by Amanda, Cone uses his ice cream truck to distract Bunsen from school so he will be expelled. Fortunately for Bunsen, with help from Mikey, he resisted the sounds of the ice cream truck, and after school, Cone offered Bunsen and Mikey his truck. In "Astro-Nots", Bunsen and Mikey ask Commander Cone to give them a tour through Outer Space, thinking he is a Mastronaut. As the episode progressed, the three of them became good friends, and with Bunsen and Mikey's help, Cone changes from ice cream vendor to an actual Mastronaut.

Trivia

 * His last name is unknown.
 * He was originally going to have a big tail until it was changed to a small tail.
 * Jeremy Rowley, the person who voices Bunsen, also plays Rate the Pain Victim from the show All That, Lewbert Sline from the show iCarly, and Amanda's fake father and a customer from The Amanda Show.
 * Butch Hartman had a drawing of a beast in 2009 which would later on be him.
 * He has been a human once in "Handsome Beast".
 * He once lived in Beast World.
 * He and Mikey are the only characters to appear in every episode.