Unstable

Garbage Elemental

Creature — Elemental

Frenzy 2 (Whenever this creature attacks and isn't blocked, it gets +2/+0 until end of turn.)
This creature can't be blocked by wordy creatures. (A creature is wordy if it has four or more lines of rules text.)

Creature — Elemental Rigger

When this creature enters, it assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Goblin

Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)
When this creature enters, roll two six-sided dice. Create a number of 1/1 red Goblin creature tokens equal to the difference between those results.

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
When this creature enters, roll a six-sided die. This creature deals damage equal to the result to target opponent or planeswalker.

Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)
Each creature you control with any kind of counter on it has art menace. (They can't be blocked except by creatures with two or more visible figures in their art.)

Last strike (This creature deals combat damage after creatures without last strike.)
Battalion — Whenever this creature and at least two other creatures attack, target creature can't block this turn.