Chorus of the Conclave

Forestwalk (This creature can't be blocked as long as defending player controls a Forest.)
As an additional cost to cast creature spells, you may pay any amount of mana. If you do, that creature enters with that many additional +1/+1 counters on it.

Catti-brie of Mithral Hall

First strike, reach
Whenever Catti-brie attacks, put a +1/+1 counter on it for each Equipment attached to it.
{1}, Remove all +1/+1 counters from Catti-brie: It deals X damage to target attacking or blocking creature an opponent controls, where X is the number of counters removed this way.

Kurbis, Harvest Celebrant

Kurbis enters with a number of +1/+1 counters on it equal to the amount of mana spent to cast it.
Remove a +1/+1 counter from Kurbis: Prevent all damage that would be dealt this turn to another target creature with a +1/+1 counter on it.

Aberrant

Ravenous (This creature enters with X +1/+1 counters on it. If X is 5 or more, draw a card when it enters.)
Trample
Heavy Power Hammer — Whenever this creature deals combat damage to a player, destroy target artifact or enchantment that player controls.