Seadra learns hydro pump at level 40.
Azumarill learn Hydro Pump at level 57.
Swampert does not learn Hydro Pump.
At level 40, Kingdra is suposed to learn Hydro Pump.
Milotic learns Hydro Pump at Level 40.
Croconaw learns Hydro Pump at level 51.
blastoise learns hydro pump at level 44
Samurott learns Hydro Pump at level 62.
The closest match for horsey is Horsea. At level 32, Horsea evolves into Seadra. Some of the many moves Horsea can learn include bubble mean, and hydro pump.
Empoleon Learns Hydro Pump At level 59/ 99Lloyd99
Marshtomp is an evolved form of Mudkip, who learns hydro pump at level 42.
It learns Hydro Pump at level 48.
blastoise learns hydro pump at 63