Progeny of Rorix

Cumulative upkeep---Put a +1/+1 counter
on Progeny of Rorix (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.)
As long as Progeny of Rorix has three or more
age counters on it, it has flying and trample.