"Put on another creature you control" includes creatures other than Benevolent Hydra that enter the battlefield with +1/+1 counters on them. If another creature would enter the battlefield with a number of +1/+1 counters on it while you control Benevolent Hydra, it enters with that many counters plus one.
2022-12-02
Each additional Benevolent Hydra you control will increase the number of +1/+1 counters placed on anther creature by one.
This creature enters with X +1/+1 counters on it.
If one or more +1/+1 counters would be put on another creature you control, that many plus one +1/+1 counters are put on it instead.
, Remove a +1/+1 counter from this creature: Put a +1/+1 counter on another target creature you control.
, Remove a +1/+1 counter from this creature: Put a +1/+1 counter on another target creature you control.