The Old Everwyrm

Trample, Reach
This creature assigns damage equal to its toughness rather than its power. Whenever The Old Everwyrm attacks or blocks put a -1/-1 counter on it

{2}: Put a -1/-1 counter on The Old Everwyrm. This ability can be activated by any player, and can only be activated during their turn, and only once.

{8}:Transform this creature. This costs {1} less to activate for each -1/-1 counter on The Old Everwyrm