Hardened Scales

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.

Reluctant Role Model

Survival — At the beginning of your second main phase, if this creature is tapped, put a flying, lifelink, or +1/+1 counter on it.
Whenever this creature or another creature you control dies, if it had counters on it, put those counters on up to one target creature.

Shalai and Hallar

Flying, vigilance
Whenever one or more +1/+1 counters are put on a creature you control, Shalai and Hallar deals that much damage to target opponent.

Quilled Greatwurm

Trample
Whenever a creature you control deals combat damage during your turn, put that many +1/+1 counters on it. (It must survive to get the counters.)
You may cast this card from your graveyard by removing six counters from among creatures you control in addition to paying its other costs.