Roaring Boulderbeast

Trample
Roaring Boulderbeast has hexproof as long as you control four or more Satyrs.
Whenever Roaring Boulderbeast attacks, you may sacrifice a Satyr. If you do, Roaring Boulderbeast gets +X/+X until end of turn
where X is that Satyr's power.
The satyrs call on him frequently.