Text (LG+errata): 2/2. ; When ~this~ is put into a graveyard from the battlefield, all creatures that dealt damage to it this turn become 0/2. (This effect lasts indefinitely.) [Oracle 2009/07/08]
See Rule 613 for the interaction of abilities that set or alter power/toughness. [D'Angelo 2008/12/20]
Extended tournaments (see Rule 913) have always banned this card.