Sneak Attack trades permanence for speed. For one red mana, it puts a creature from your hand onto the battlefield with haste, then schedules that creature for sacrifice at the next end step. The mana cost printed on the creature no longer determines that activation's payment, allowing a red deck to deploy enormous threats while keeping mana for another creature or protection.
Creatures with entry, attack, and death abilities are especially productive. Archon of Cruelty in a deck with black can trigger on entry and again when attacking. An Eldrazi with annihilator can attack immediately, although any cast trigger is skipped because the creature was not cast. Wurmcoil Engine can leave tokens after the scheduled sacrifice, preserving resources beyond the temporary attack.
The sacrifice happens at the beginning of the next end step. Activating after an end step has already begun can delay that sacrifice until the following end step, potentially letting a creature remain through your next turn. You still need to choose a legal activation window and account for the creature's survival in the meantime.
The enchantment needs a hand of worthwhile creatures to operate; it does not find them by itself. Card draw and graveyard recovery help maintain the supply, while a normal ramp plan can keep the large creatures useful when Sneak Attack is unavailable. Plan what each temporary creature produces before it leaves. A single large attack is good, but a combination of entry value, attack triggers, and death rewards can make the same one-red activation far more difficult for an opponent to trade against efficiently.
