It is an HM that can be used to traverse any body of water, usually very needed in the game to access areas that one could not access without it.
At some points in the game, if you can't surf, you will not be able to advance any further.
It is also an extremely cool water attack, but in double battles, it can hurt or even Faint out a teammate.
I think that it might usually be learned around the 4th Gym Battle, but it really depends on which version you are playing.
No, Togepi cannot learn Surf.
No. Seviper cannot learn surf.
Vanillite cannot learn Surf.
Slowpoke does not learn Surf by levelling up, but it can learn Surf via HM in all generations.
Yes, Zigzagoon is able to learn Surf.
You have to use the HM surf It does not learn surf by leveling
No, Togepi cannot learn Surf.
No. Seviper cannot learn surf.
Vanillite cannot learn Surf.
One can learn how to surf from websites like About, Away, Lajolla Surf, Surfing Waves, Learn to Surf, wikiHow, Surf Science, New Quay Surfer, Surf Noosa and Dano Surf.
Slowpoke does not learn Surf by levelling up, but it can learn Surf via HM in all generations.
Yes, Marill can learn Surf.
No, it cannot learn Surf.
Yes, Marill can learn Surf.
Yes, Zigzagoon is able to learn Surf.
YES! It is a water Pokemon and can learn to surf.
Manaphy cannot learn Surf but it can be taught it via the Surf HM.