Rancid Rats

The pairing is the whole point: skulk and deathtouch on the same small body solve the problem deathtouch usually has, which is that a 1/1 with deathtouch threatens combat but rarely connects with anything worth threatening. Defenders simply block it with whatever they want to trade. Skulk inverts that math. Because the creature can only be blocked by something with equal or lesser power, the opponent's bigger threats (exactly the ones deathtouch most wants to trade with) are barred from the block. A board of fat midrange beaters cannot interpose itself. The result is a recurring evasive threat of mortal damage: every point it deals to a blocker kills that blocker, and the only legal blockers are the small ones the opponent would rather not throw away. It also makes a clean attacking deterrent in reverse, since swinging in over a deathtouch body still risks the chump. The mechanics here read as filler until you notice they are answers to each other's weaknesses; skulk dodges the big creatures, deathtouch punishes the small ones, and a 1/1 ends up dictating combat above its weight. That kind of two-keyword interlock, where each ability covers exactly the gap the other leaves open, is a tidier piece of common-rarity design than the stat line lets on.