Overwhelming Stampede

Until end of turn, creatures you control gain trample and get +X/+X, where X is the greatest power among creatures you control.

Aggressive Mammoth

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Other creatures you control have trample.

Ferocity of the Wilds

Attacking non-Human creatures you control get +1/+0 and have trample.

Archetype of Aggression

Creatures you control have trample.
Creatures your opponents control lose trample and can't have or gain trample.

Proud Wildbonder

Trample
Creatures you control with trample have "You may have this creature assign its combat damage as though it weren't blocked."

Akroma's Memorial

Creatures you control have flying, first strike, vigilance, trample, haste, and protection from black and from red.

Meet and Greet "Sisay"

Whenever you cast a spell, choose one —
• Flavor — Meet and Greet "Sisay" gets +1/+1 until end of turn for each line of flavor text that spell has.
• History — Create a Treasure token if that spell doesn't share an expansion symbol with a permanent you control or a card in your graveyard.

Street Riot

During your turn, creatures you control get +1/+0 and have trample.

Exoskeletal Armor

Enchant creature
Enchanted creature gets +X/+X, where X is the number of creature cards in all graveyards.