- "I'm the most efficient medical droid in the Galaxy, even more capable than Effex-Seven. And certainly possessing a better bedside manner."
The droid was highly sophisticated, belonging to the older, yet remarkably astute 2-1B series. Because of his intellect, Too-Onebee was fiercely independent and morality-driven. His gentle touch can be attributed to his precise hydraulic systems, which utilized several liquids at different temperatures.
One of Too-Onebee's earliest assignments found him serving the Galactic Empire on the planet Firro, a world recently subjugated by the Imperials. There, he was tasked with providing medical care to the civilians of Firro who were injured by Imperial atrocities. It was Too-Onebee's thankless job to mop up after what the Empire had left of the people there. After months of treating an unending parade of wounded, the number of people coming to see Too-Onebee began to decrease as the Empire settled in for a long occupation of the planet. It was then that the talented medical droid came under notice of Lord Cuvir, the newly proclaimed Governor of Firro while on an inspection of a crowded relief station. Cuvir, seeing the droid's determined efficiency and skill, took Too-Onebee as his own personal physician, ignoring the needs of the civilian wounded. Too-Onebee was distressed at having to leave the large numbers of wounded and disapproved of his new master's overbearing ways, but was forced to serve him faithfully in accordance with his overriding programming directive—to heal living beings no matter whom they might be. Nevertheless, he longed to serve those he thought were on the "right" side.
Too-Onebee's opportunity to do the "right" thing would soon come. He accompanied Lord Cuvir on a visit to the planet Wor Tandell. While inspecting the medical facilities at the governor's mansion, he witnessed the assassination of Cuvir at the hands of one of the governor's aides. Staying true to his programming, Too-Onebee attempted to treat the mortally wounded Cuvir, despite believing him to be the most evil being he had ever encountered. The droid soon discovered the aide to be an undercover Rebel agent who identified himself only as Tiree. The man was, in actuality, agent Tay Vanis. Vanis had been secretly collecting information on Imperial fleet movements in the Tandell system when he was discovered by Cuvir. Vanis was forced to kill the Governor to protect his mission. Too-Onebee believed the man, having long dreamed about the rumored Rebellion. He accompanied Vanis in his escape and joined the Rebel Alliance. The droid served with Vanis on a few missions before being assigned to his most important role for the Rebellion.
Along with FX-7, Too-Onebee arrived at Echo Base on Hoth and was quickly assigned as the head of the base infirmary. Too-Onebee was named chief of surgery. The two medical droids treated a variety of injuries and patients, including Luke Skywalker's wampa scarring in 3 ABY. After the Battle of Hoth, Too-Onebee was evacuated aboard the GR-75 medium transport Bright Hope. After the transport was destroyed attempting to run the Imperial blockade, Too-Onebee reached the Rebel underground on the planet Darlyn Boda, where he served for a short time, before finally reaching the secret Rebel rendezvous point. There, he was immediately assigned to the EF76 Nebulon-B escort frigate Redemption to treat surviving wounded from Hoth.
Luke Skywalker was so impressed with the droid's skill and expertise that he specifically requested him to treat the wounds he sustained in his battle with Darth Vader on Bespin while recovering aboard the Redemption.
Behind the scenes
For a brief period, 2-1B had his own regular column in various official Star Wars magazines. In this short-lived feature he would respond to reader mail. He was portrayed as having a large ego, constantly mocking FX-7 and claiming that he was the hero of the Rebellion for such acts as saving Luke Skywalker. This was referenced by Daniel Wallace with the quote that accompanied 2-1B's entry in The New Essential Guide to Droids. The article was a "response" concerning how Mara Jade, an Expanded Universe character, was given a model and the cover of the Star Wars Insider, while 2-1B, a character who was actually from the films, was not given a cover shot.
Two 2-1B units are seen working on Darth Vader in the Imperial rehabilitation center on Coruscant at the end of Star Wars: Episode III Revenge of the Sith; but neither of them is intended to be the same unit droid shown in Star Wars: Episode V The Empire Strikes Back, who heals Luke's injuries from the Wampa and repairs his hand after his duel in Cloud City.