8P-MD-4 was a medical droid PC introduced in Session # 10 and lost (to the dread anomaly) in Session # 14. Now, having a medical droid on hand seems like a great idea, and 8P-MD-4 had his share of memorable moments: wrestling with Marpa over a power slug, falling off a bridge into a bottomless abyss, holding off attackers at a key point on the roof of a sandcrawler, and more. You'll notice that none of these examples involve healing or medicine in any way, and I think that's mainly because the player running 8P-MD-4 kept forgetting that the character had the vaunted Surgery feat and could have been quite handy to his fellow PCs. Still, it's unfortunate that after 8P-MD-4, no PC has ever been a droid since. (though rumor has it that if we ever do a Rebellion-era campaign, that may change . . .)
Long after his disappearance into the vagaries of the anomaly, 8P-MD-4 reappeared in the campaign; or at least, his head did, as it contained vital recordings of the anomaly's energy signature, a fact which has driven multiple story arcs in the latter half of the campaign.