Hired Poisoner

The cheapest possible packaging of deathtouch on a body, and the math is the whole appeal. A 1/1 normally dies to a 2/2 and accomplishes nothing, but deathtouch rewrites combat arithmetic so that any blocker, regardless of size, trades down to it for the price of a single mana. That turns it into both an aggressive tempo tool (early pressure that opponents cannot profitably block) and a defensive deterrent that no fatty wants to attack into. Left to its own devices, it is a one-shot: throw it into combat and it kills whatever it touches, but it takes the return damage and dies in the trade. Where it becomes an engine is any effect that lets it ping without stepping into damage, since deathtouch means a single point of pinged damage is lethal to anything it hits, turning one black mana into repeatable removal. Grant it first strike and the combat downside vanishes entirely: it strikes, the blocker dies before it can hit back. What keeps a lone copy honest is exactly what makes it elegant: no evasion, no way to make itself relevant, so it has to connect or block to matter, and an opponent holding creatures back can simply refuse to give it a target. Pricing deathtouch at the absolute floor with no additional text is the design at its most honest: poison on legs, nothing else, and that alone is enough to warp a combat step.