Valan Yuhr, Adept Lifecrafter

At the beginning of your end step, put a +1/+1 counter on each untapped Treefolk creature.
Whenever a Treefolk creature you control attacks, remove all +1/+1 counters from it, then create that many 0/1 green Plant creature tokens.
{g}{t}, Sacrifice X Plant creatures: Search your library for a Treefolk creature with toughness X or less and put it onto the battlefield, then shuffle your library.