Flygon doesn't naturally learn either of those moves.
Flygon cannot learn Earthquake by leveling up, you have to use TM26.
Glaceon can learn crunch.
It doesn't learn Crunch at all.
With a TM.
No, Flygon cannot learn Dig by leveling up. You will need to use the TM to teach it Dig.
Blastoise never learns Crunch. Blastoise does not learn Crunch, but it does learn Bite. This is when it is a Wartortle (or Squirtle) and is on level 16. If you have a Blastoise on level 16 (which is not really possible), it will learn Crunch.
Flygon can only be taught Outrage through a Move Tutor.
Hyper beam, Earthquake, Rock Slide, Crunch. Think about Flygon's stats Its a physical pokemon A better moveset: Crunch, Earthquake, Dragon Claw, Fly.
Gyarados cannot learn crunch by any means
Arcanine itself cannot learn Crunch from leveling. However it's unevolved form, Growlithe, can learn Crunch at level 42. You can also hatch a Growlithe with the move Crunch via breeding.
It doesn't learn Crunch at all. Not even through breeding or TM.