Jade Ouroboros

{t}: Gain {g}
Whenever a land enters the battlefield, add a land counter to Jade Ouroboros.
{t}: Remove X land counters for Jade Ouroboros. Target creature gains +X/+X. If there were more
than six land counters on Jade Ouroboros, it also
gains trample until end of turn. If there were
more than 12 land counters on Jade Ouroboros, it also gains double strike until end of turn.
You look right just in time to see a dog grow ten times it's original size.