Tangletrove Kelp

Clue tokens are colorless artifacts that sit inert until you pay to crack them: two mana, sacrifice, draw a card. This turns that pile of stored cantrips into a combat threat without ever asking you to give up the card underneath. At the beginning of each combat, every other Clue you control puts on a 6/6 Plant body while keeping its artifact-and-Clue types intact, which means the tokens can still be sacrificed for their draw after they've attacked, or held back and cashed in later. That layering is the whole trick: the Clues never stop being Clues, so animating them costs you nothing but the attack step, and the mana investment you already made assembling the board pulls double duty as a beatdown. The card is also a Clue itself, ward-protected, with its own crack-for-a-card built in, so even in a shell that produces no other investigation tokens it degrades gracefully into a large body and a replacement draw. Investigate has been a repeating mechanic across several sets, and most of its payoffs reward you for the artifacts as artifacts (affinity, improvise, sacrifice fodder). This is one of the few that rewards the token count itself as a battlefield, converting a value engine's accumulated bookkeeping into a mass of green-ish beef the turn you decide to swing.