Titanoboa

{6}{g/u}{g/u}: Monstrosity 5. (If this creature isn't monstrous, put 5 +1/+1 counters on it and it becomes monstrous.)

Wither
{g/u}{g/u}{g/u}: Target creature you control gains wither until end of turn.
Titanoboa is an extinct genus of snake from what is now La Guajira in northeastern Colombia.