Level Up

Enchant creature
When this Aura enters, put a +1/+1 counter on enchanted creature.
Enchanted creature has "Whenever this creature attacks, double the number of +1/+1 counters on it. Then if it has power 10 or greater, draw a card."

Spider-Man, Miles Morales

Vigilance, trample (Attacking doesn't cause this creature to tap. He can deal excess combat damage to the player he's attacking.)
Whenever Spider-Man enters or attacks, put a +1/+1 counter on each other creature you control. Those creatures gain trample until end of turn.

Vigor

Trample
If damage would be dealt to another creature you control, prevent that damage. Put a +1/+1 counter on that creature for each 1 damage prevented this way.
When Vigor is put into a graveyard from anywhere, shuffle it into its owner's library.

Power Fist

Equipped creature has trample and "Whenever this creature deals combat damage to a player, put that many +1/+1 counters on it."
Equip {2}

Leatherhead, Iron Gator

Trample, haste
Whenever Leatherhead attacks, put two +1/+1 counters on each creature you control.

High Score

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.
At the beginning of your end step, draw a card if you control a creature with the greatest power among creatures on the battlefield.

Voracious Hydra

Trample
This creature enters with X +1/+1 counters on it.
When this creature enters, choose one —
• Double the number of +1/+1 counters on this creature.
• This creature fights target creature you don't control.