Linoone and Slaking.
Certain Pokemon can learn that move like Slaking and Linoone, it's not a TM or move tutor move so your going to have to learn it via level or breeding.
I used the TM of covet on mine but it actually learns it some where in pkmn ruby sapphire firered leafgreen emerald diamon pearl platinum hg & ss somewhere between level30-level50 but good luck
linoone at level 35 i think
Lvl 31
In Pokémon SoulSilver, Mankey will already have Covet as a beginning move and if it doesn't have it as a move when caught then you just need to take a Heart Scale to the Move Re-learner in Blackthorn City in order to teach Covet to it.
No, Sceptile cannot learn Blizzard.
Yes, Marill can learn Surf.
The following Pokemon that you can easily get to learn Flash in Sapphire: Beautifly or Dustox Lotad or Lombre Oddish Gloom
No, Heat Wave is a Generation IV move. Sapphire is a Generation III game. CHARIZARD can't learn it with Sapphire, but Diamond, Platinum, HeartGold... they'll all work!
It can learn it via the TM but not by level.
yes,camerupt will learn fissure it will learn it at Lv.55
With a HM 06