Shelob, Child of Ungoliant

The killing part is the mechanic that carries this card, and it inverts what "trading in combat" usually costs you. Every Spider you control already hands out deathtouch, so any block or attack is lethal on contact; the second ability then converts the corpse of whatever your Spider poisoned into a Food copy of that creature, stripped of every card type but artifact. What looks like a life-gain rider is really a repeatable theft engine: block an opposing bomb with a token Spider, watch it die to deathtouch, and keep a neutered copy that sacrifices for three life instead of ever attacking you again. The trigger reads on any creature a Spider damaged, so it does not require the Spider to survive, only to have connected. Ward on the whole team is the tax that keeps the web intact, punishing the spot removal that would otherwise unravel a board built on cheap deathtouch bodies. Black-green has long owned the "your death is my resource" space through sacrifice payoffs and reanimation, but this pulls the loop earlier: the value is banked the moment your Spider deals damage, not after you sacrifice something of your own. The Spider Demon typing and the tie to Ungoliant's brood give it an obvious tribal home, but the design reaches past flavor: it is a deathtouch lord whose reward for winning combat is quietly disarming the opponent, one Food at a time.