Kalonian Hydra

Trample
This creature enters with four +1/+1 counters on it.
Whenever this creature attacks, double the number of +1/+1 counters on each creature you control.

Bloomburrow Commander

Trample
Kalonian Hydra enters with four +1/+1 counters on it.
Whenever Kalonian Hydra attacks, double the number of +1/+1 counters on each creature you control.

March of the Machine Commander

Trample
Kalonian Hydra enters the battlefield with four +1/+1 counters on it.
Whenever Kalonian Hydra attacks, double the number of +1/+1 counters on each creature you control.

Incluso los báloths le temen cuando es su hora de comer.

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To double the number of +1/+1 counters on a creature, determine how many +1/+1 counters are on the creature and put that many more on it. Effects that interact with counters (such as the one created by Corpsejack Menace's ability) may change the number of counters ultimately put on the creature.