Secret Lair Countdown

Creature — Dog

Discard a card: This creature gets +1/+1 and becomes the color of your choice until end of turn.

Wild Mongrel

Secret Lair Drop

Creature — Beast Horror

When this creature enters, destroy target creature an opponent controls.

Ravenous Chupacabra

Creature — Hydra

Trample
Whenever a player casts a spell, put a +1/+1 counter on this creature.

Managorger Hydra

Creature — Goat

Whenever this creature attacks, creatures you control gain trample and get +X/+X until end of turn, where X is the greatest power among creatures you control.

Pathbreaker Ibex

Creature — Cat

{1}{G}: You may return another creature you control to its owner's hand. If you do, this creature gains indestructible until end of turn.

Temur Sabertooth

Creature — Snake

If one or more counters would be put on an artifact or creature you control, that many plus one of each of those kinds of counters are put on that permanent instead.
If you would get one or more counters, you get that many plus one of each of those kinds of counters instead.

Winding Constrictor

Creature — Crocodile

Bloodthirst 1 (If an opponent was dealt damage this turn, this creature enters with a +1/+1 counter on it.)
Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

Lurking Crocodile

Snow Creature — Snake

Flash
Flying
When this creature enters, draw a card.
This creature has deathtouch as long as you control at least three other snow permanents.