Mephitic Ooze

Deathtouch by another name, built before deathtouch was a keyword. The combat-damage clause does the structural work: anything it bites dies and cannot be regenerated, which on a 0/5 frame means a body that can sit in front of any attacker and trade up the moment it carries even a sliver of power. That last condition is the catch, because out of the box this deals zero combat damage, so the destroy trigger never fires. It needs power to do anything, and the only source of power is your artifact count. One artifact turns it into a 1/5 that kills whatever it touches: passive on offense but ferocious on defense, since a single point of combat damage is enough to make the destroy clause fire. The two halves pull in opposite directions. The damage-kills effect rewards connecting for the smallest amount possible, while the body is so inert that it cannot threaten the red zone until your artifact count climbs. It is a clean snapshot of how the destroy-on-damage effect was costed in an early era, when the ability that would later become a common keyword on one-drops still had to be paid for with a build-around restriction and a creature that could not act on its own. The artifact-scaling line is the price; without it, the kill ability is inert text.