Ratchet is the head medic of the Autobots in the Transformer comic and TV series. He is one of the original and longest continued characters from the Tranformers universes.
Characterized as a healer, Bob Budiansky named him after Nurse Ratched from the movie One Flew Over the Cuckoo’s Nest. His vehicle mode is an ambulance and has two robot modes, although he only changed into his second form in the toy line as he usually used the other one in the comic and TV series. He was quite a popular favorite as his courage and loyalty often manifests.
Ratchet had his debut appearance in the #1 issue of the Transformers comic book series by Marvel Comics. It was originally planned as a 4-issue series, but then ran to a monthly installation up to eighty issues. It was in issue #4 Sparkplug Witwicky was rushed to the hospital by Ratchet after having a heart attack aboard the Ark, the Autobot base. This saved him from the retaliation of the remaining Decepticons (mainly by the Decepticon Shockwave) after Witwicky has damaged most of them by tainting their fuels. Shockwave managed to destroy all of the Autobots but Ratchet found a way to restore his fellow Autobots to overcome the Decepticons.
In his quest to revive the Autobots, he almost had a deal with Megatron: that Ratchet would defeat Shockwave (for Megatron was formerly humiliated by Shockwave by beating him and demoting him to an ancillary leadership rank) and the Decepticon will free the captured Autobots. But of course Ratchet knew that Megatron will turn against him, so he looked for other ways to get out of it. He came up with the Ark’s research for “life” on the planet where the vessel first crash landed. And as they are from a mechanical-based reality, they conceived that the moving metallic objects in the area are a proof of life. However, the only living creatures that are of the same size as the Transformers are the dinosaurs, so The Ark fashioned the Dinobots after them. This started Ratchet’s search for the Dinobots and bringing them back to life.
When he had his five Dinobots, Grimlock, Slag, Sludge, Snarl and Swoop, he confronted Megatron which only dismissed them and insulted the medic. Desparate, Ratchet threw himself to the Decepticon in hopes that both of them will fall off the cliff, finishing them both. Ratchet ended up bouncing off and being laughed at by Megatron, although the latter complemented his courage. But all hopes aren’t dead as apparently, Ratchet has damaged the cliff edge where Megatron was on, as it collapsed and the fall caused the Decepticon’s deactivation.
Ratchet is a hero but he wasn’t feeling any joy. So he returned to The Ark with the Dinobots and repaired his comrades, all except Optimus Prime whose head was still missing to be later revealed as in Shockwave’s hands for his interest to access the powers of the Matrix.
You can find more Ratchet concept art images for Transformers 2 @ downloads page.