Furtive Homunculus
Furtive Homunculus SOI
Shadows over Innistrad Common 
Cost: Mana 1Mana U
CMC: 2
Card Type: CreatureHomunculus
Power/Toughness: 2/1
Oracle Text: Skulk (This creature can't be blocked by creatures with greater power.)
Flavor Text: "In terms of intelligence, homunculi are somewhere between humans and skaabs—clever enough to follow more complex orders, but dim enough to not question them."
—Stitcher Geralf
2016-04-08 Skulk matters only as blockers are chosen. Modifying either creature’s power after blockers are chosen won’t cause the attacking creature to become unblocked.
2016-04-08 If you cause a creature to have 0 power or less, use the actual value (which may be negative) to determine whether it can block or be blocked. A creature with skulk and 0 or less power most likely won’t be blocked, but it won’t deal combat damage and won’t trigger any abilities that trigger when combat damage is dealt.