Minimum stats are calculated with 0 EVs, IVs of 0, and a hindering nature, if applicable.
Maximum stats are calculated with 252 EVs, IVs of 31, and a helpful nature, if applicable.
– Suggested moveset
Wailord would be most strong with these moves:
Hidden Power (this would be Grass type)
I would give Wailord the Choice Specs as its item.Remember that the Choice Specs raise Special Attack by 50%, but they lock the holder into one move. I would choose Surf as that move, as it damages both of the opponents. You might want to choose Water Spout as that move (as it has 150 power), but you must remember that it only has 5pp and that it becomes weaker the more damage your Wailord takes.
If you don’t want to use the Choice Specs, you can always use Leftovers. Leftovers give you small amounts of health during the battle, but in the long run they might make the difference between you winning or losing.
You can also damage other water type Pokémon with Hidden Power, which means your Wailord might have a chance against Pokémon such as Blastoise.
– Type defenses
All in all, Wailord is a great Pokémon, and it is very underrated. Try one out in your team and see how it goes!