Who is this Skippy, you may ask, and how did he get shoved into my late lamented Expanded Universe? Well, to a certain extent, you've already met Skippy, way back in 1977 when droids were droids and the actors who played the Jawas weren't Ewoks yet. Please cast your time-travel-seeing eye to this scene in Star Wars, where the surely-series-derailing choice of Uncle Owen to pick a red R-5 unit rather than our blue pal R2-D2 was such a close call that even Darth Vader issued a sigh of relief:
Panels from Star Wars (1977 Marvel series) #1 (July 1977), script by Roy Thomas, pencils and inks by Howard Chaykin, colors by Marie Severin, letters by Jim Novak
Wait, just what was Luke going into Tosche Station to do before Uncle Owen so rudely interrupted him? We in Star Wars fandom will never know.
Just as every creature in the Cantini scene later had their completely backstory detailed in the Expanded Universe, so too was this ill-fated little R-5 droid's tale revealed by Peter David, first in his "But I Digress..." column in Comics Buyer's Guide and later self-adapted in the very first issue of it-aint-always-canon Star Wars Tales.
Panel from "Skippy the Jedi Droid" in Star Wars Tales #1 (September 1999), script by Peter David, pencils by Martin Egeland, inks by Howard Shum, colors by Harold MacKinnon, letters by Vickie Williams
Skippy was quite possibly the only purely mechanical being in the Star Wars Expanded Universe who could use the Force, which is a dandy concept in so many ways, chiefly that it completely invalidates the idea of biological midichlorians.
Three cheers for Skippy! No midichlorians!
OH FOR PETE'S SAKE STAR WARS
Anyway, Skippy escapes and lets himself be taken in by Jawas so that he can live that soft, plush, Sandcrawler-pimp life...
It's around this time in any self-respecting Expanded Universe story that the protagonist crosses paths with one or two G-Canon Characters, because, as we all know, you are only defined as a supporting character in someone else's saga. For example: I myself know that I'm an important but peripheral supporting character in the canon life story of Jane Wiedlin.
Now, another retelling of the Star Wars saga, which can take place in only one panel because it's only twenty minutes into the movie. Also, it's a good place to dump all the wry and sardonic Peter David "jokes" into a caption box where we can just ignore them for a cinnamon roll visual.
The rest of the story? Well, you know it by heart. Skippy, the red R-5 unit initially chosen by Uncle Owen "You're Going to a State School and You'll Like It" Lars, realizes that it's not himself but true blue R2-D2, possessor of the Death Star blueprint data and all of Darth Vader's embarrassing LiveJournal poetry, must be the droid to accompany Luke Skywalker and finish out the rest of the trilogy and the one before that and maybe there's be a seventh one someday. So Skippy selflessly, bravely, canonically does a Dr. Kevorkian on himself so that Artoo gets to stay with Threepio. Because, as you know, always two there must be.
CUE THE SWELLING TONES OF SAD BUT TRIUMPHANT JOHN WILLIAMS JEDI THEME MUSIC
Later, in his controversial biography There Are You, Force? Yoda, It Is, Jedi Master Yoda contested the truth of this whole story when he wrote "Never a droid Padawan had we. Confused and poorly programmed, must he be, remembering not things as were they, but kind some of universe expanded, was it." Then again, Yoda did spend four chapters of his autobio frantically trying to refute the rumors of his passionate affair with Yaddle, so take that however you want to.