From the Super Mario Wiki
Bunsen is a robot who inhabits the city of Robo Land. She is a close friend of Dr. Nerdnick, and may even be his own creation, although her origin was never really explained. Bunsen appears to have some sort of artificial intelligence, as she is capable of having conversations with other characters and can think for herself.
The Super Mario Bros. Super Show!
Bunsen appeared only in The Super Mario Bros. Super Show! episode "Robo Koopa". She made her entrance by extending her arm from offscreen, and used it to reprogram Robo Koopa's Robo Suit when he was attacking Mario, Luigi, Princess Toadstool. With Robo Koopa unable to control himself, Bunsen greeted Princess Toadstool, whom she had apparently already met at some point prior to the events of the episode.
Bunsen took Mario's group down a tunnel to Dr. Nerdnick's workshop, explaining that King Koopa had duped Dr. Nerdnick into building him the robo suit. She then led them into the workshop, where she was able to free Dr. Nerdnick while the others fought off the Robo Shy Guys that were guarding the place. Eventually Robo Koopa returned. When he couldn't get the Robo Suit to work properly, Bunsen accidentally interpreted Dr. Nerdnick's comment, which allowed Robo Koopa to capture Princess Toadstool and Toad in force fields. Despite this, Bunsen managed to escape with Dr. Nerdnick, Mario and Luigi,
After a close call, Bunsen and the others eventually escaped from Robo Koopa and wound up in a junkyard. In the junkyard, Bunsen helped Dr. Nerdnick assemble the Plumbinator, and cheered Mario and Luigi on as they used it to fight Robo Koopa.
Robo Koopa succeeded in destroying the Plumbinator, and managed to capture Dr. Nerdnick. Bunsen interpreted Dr. Nerdnick's next message, telling Robo Koopa to press a particular button on his robo suit in order to stop it from running out of fuel. What she had interpreted was a lie, as the button was for the ejector seat, which sent King Koopa flying out of the robo suit and into the sky.
Afterwards, Bunsen spoke for Dr. Nerdnick, who rewarded Mario and Luigi with the robo suit, which he had converted into a robo pizza oven just for them.
Powers and abilities
Bunsen is capable of extending her arms telescopically, allowing her to reach her target with little difficulty. She can even extend her individual fingers in the same fashion, which is practical for tasks such as pushing numerous buttons.
Bunsen is multilingual, as she is capable of understanding the unknown language spoken by Dr. Nerdnick. As such, she is the only known character who understand him and had to serve as an interpreter between him and the other characters. However, Bunsen is programmed to translate anything that Dr. Nerdnick says, regardless of whether or not he wanted other characters to understand him.
Bunsen can also open up her chest plate to reveal an automated screwdriver.