An 8/8 trample for six is a finisher anywhere, but the floating green is what decides where this sits in the draft. The trigger does nothing the turn you cast it: the ability only functions once the body is on the battlefield, so the lands you tap to pay for the never see it. What it changes is every land drop after. From the next turn on, each tap nets a second green, which in a slow base-green deck turns turn seven onward into a different game. TMT's utility-land density (Escape Tunnel, TCRI Building, Foot Headquarters) means that doubled mana funds the activations the format normally taxes you for.
The home is BG goodstuff or a Sultai pile splashing for the food and legendary payoffs, where the format's good fixing makes the GG trivial off a green base. P1P2 to P1P4 in any deck already committed to green: ahead of most uncommons, behind only the mythic legends and hard removal. It needs you to already be the slow deck, and TMT's medium speed means you do have to survive to six before the engine matters.
The punisher is Dimensional Exile: same cost, no two-for-one risk, turns the 8/8 into a blank, and every white deck runs it. Stomped by the Foot answers it cleanly too. Trample carries more weight than the rate suggests, because a chunk of TMT's defensive commons stop at two toughness, and the Sneak creatures that race past you can't block the turn they arrive. Maindeck in any green deck that opens it.

