EDIT: Lol, someone told me a couple of these look "familiar". They're up on the old sprite repository from before the split. If any of them made it into the game, neato. I've not played much in ages so I was unaware.
A plasma cutter/torch. Intended to be a researched upgrade from R&D.
Several shotgun shells. Orange is pepperspray, Black is consecrated, and blue is anti-armor.
Several hairstyles. A modified braid, the Rachel, and Lemmy of Motorhead's facial hair. The hard to see one is a Hulk Hogan-style skullet.
A set of tacticool operator goggles and a balaclava for operating tactically
A Vampiric Horror. Was an idea I had for a more conspicuous form that the Vampire could take a-la Symphony of the Night.
A smashed Keeper. Someone on NT had the idea for them and I just goofed around a little with it to make a more beat up looking sprite for when they'd get destroyed or scrapped.
A full set of red cybernetic augmentations (including an alternate female torso with breasticles)
Molten rock people. I'm not going to stop until I can weasel this fella' into Asteroidstation
From here on I can't really claim ownership. Most of these are pre-existing sprites that I've spruced up with better alpha masks or idle animations in some cases. (A couple are sort of difficult to see because of the transparency. It's not an issue in-game.)