Historical Rules · 30 September 2011
Rule 702.56a
Official source text from the 30 September 2011 Rules release
Graft represents both a static ability and a triggered ability. "Graft N" means "This permanent enters the battlefield with N +1/+1 counters on it" and "Whenever another creature enters the battlefield, if this permanent has a +1/+1 counter on it, you may move a +1/+1 counter from this permanent onto that creature."