Tyrranax Rex

This spell can't be countered.
Trample, ward {4}, haste
Toxic 4 (Players dealt combat damage by this creature also get four poison counters.)

Rust Goliath

Prototype {3}{G}{G} — 3/5 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
Reach, trample

Trample
Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Trample
When Ghalta, Stampede Tyrant enters, put any number of creature cards from your hand onto the battlefield.