Oomvald, Goblin Leader

All goblins you control have frenzy X, where X is the number of goblins you control. (Whenever this creature attacks and isn't blocked, it gets +X/+0 until end of turn.)
When this creature enters the battlefield, gain control of target permanent with converted mana cost less than, or equal to the number of goblins you control.
"We are strong in numbers, so stay together!"