During the first season of The Muppet Show, Bunsen Honeydew presented the Muppet Labs segments by himself; Beaker was added as his lab assistant from the second season on. Beaker has googly eyes, a shock of red hair, and a drawbridge mouth. He was originally puppeteered and voiced by Richard Hunt until Hunt's death in 1992, when the role was taken over primarily by Steve Whitmire.
Dr. Bunsen Honeydew's name was derived from the traditional piece of lab equipment, the Bunsen burner, plus the fact that his head was shaped and colored like a honeydew melon. He was rumored to be modeled after Lew Grade, whose company ITC Entertainment produced The Muppet Show. Henson responded in a Judy Harris interview:
Meep meep meep! Everyone knows who the narrow headed assistant to the scientist at Muppet labs, but fewer know Dr. Bunsen Honeydew. Together these two characters made us laugh with every visit to Muppet Labs. Ultimately Dr. Honeydew would discover or invent something, and, unfortunately for Beaker, he always needs an assistant for testing. Beaker would inevitably have the experiment go terribly wrong, unnoticed by Dr. Bunsen Honeydew, who would be explaining what should be happening to the audience. Dr. Honeydew is my favorite muppet, and now, along with his assistant, the first Muppet(s) to make our Geek of the Week list.
According to Muppet Wiki, Dr. Bunsen Honeydew is the resident scientist on The Muppet Show and host of Muppet Labs segments. In Season 1, he worked alone. In Season 2, his assistant Beaker was added to the show. He showed the audience his inventions with excitement such as the gorilla detector, exploding hats and the copying machine. Beaker is the eager assistant of Dr. Bunsen Honeydew. He made his first appearance on Muppet Labs sketches in the second season of The Muppet Show. He always communicates with his high-pitched Meep-meep-meep noises. When he tried Bunsen's inventions, he had been shrunk, cloned, deflated, turned invisible, and blown up, but he always came back for more.