There is a house on route 228 and there is an elder that will teach Pokemon "special" moves to "special" Pokemon he has a note on wall which Pokemon can learn those moves.
it does not learn hydro cannon you have to get the tm hydro cannon
Lugia does not learn hydro cannon nor can learn hydro cannon.
No, Palkia is not capable of learning Hydro Cannon.
feraligatr learns hydro cannon at level 74
Gyarados cannot learn the move Hydro Cannon. Hydro Cannon is a move that can only be learned by the Water type Starter Pokemon.
he learns hydro pump at in leve 50 something, and a lady in two island teaches him hydro cannon
swampert can not learn hydro cannon in R/E/S it can only learn hydro cannon in Pokemon pearl/platinum/diamond SEE YA
there's no TM for hydro cannon. u have to get national dex and tutor it.
The only Pokemon that can learn Hydro Cannon are: Blastoise, Feraligatr, Marshtomp, and Empolion.
A move tutor on two island will teach it hydro cannon if its level 50.
You shouldn't bother teach it hydro pump cause it has hydro cannon.
Empoleon learns metal claw, drill peck, aqua jet, hydro pump, i think icebeam, and hydro cannon. best movesare drill peck, hydro pump, and hydro cannon(hydro cannon makes you recharge though)