Grasslands Wurm

Trample
Cumulative upkeep—Put a -1/-1 counter on
target creature you control. (At the beginning of
your upkeep, put an age counter on this permanent,
then sacrifice it unless you pay its upkeep cost for each
age counter on it.)
"What is that grin? Maybe a wurm is coming behind
us?"
—Taaveti, to Amaril