You're thinking of screwjank clunker which is quite playable. Junkbot is a neutral 1/5 that gets +2/+2 when a friendly mech dies. Mech is generally aggro so he doesn't help there. I thought about maybe a hunter w/ feign death if it counted as things dying, but that just isn't practical and a bit redundant since it is kinda an anti-aoe card and harvest golems/piloted things are already anti-aoe, it might fit best in a priest mech deck, but they have the much better upgrade bot in the 5 slot. Hmmmm...maybe a shaman deck w/ deathrattle mechs and reincarnate.