Arcane Clockwork Wurm

Trample
At the beginning of your upkeep put a +1/+1 counter on Arcane Clockwork Wurm.
{t}: Remove a +1/+1 counter put a -1/-1 counter on target creature
{2}{t}: Remove five +1/+1 counters destroy target permanent
{5}{t}: Remove ten +1/+1 counters take a turn right after current turn (use this ability only as a sorcery.)