Secret Lair Drop

Creature — Fish

When this creature enters, double the number of each kind of counter on any number of target permanents.

Deepglow Skate

Legendary Creature — Elemental Lizard

Whenever a commander you control deals combat damage to an opponent, it deals that much damage to each other opponent.
Partner (You can have two commanders if both have partner.)

Kediss, Emberclaw Familiar

Poison Counter

Sorcery

Until end of turn, creatures you control get +1/+1 and gain trample and infect. (Creatures with infect deal damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)