Moves it learns by leveling up in Emerald:
Lv 7 - Harden
Lv 10 - Vicegrip
Lv 13 - Leer
Lv 20 - Bubblebeam
Lv 23 - Protect
Lv 26 - Knock Off
Lv 32 - Taunt
Lv 35 - Crabhammer
Lv 38 - Swords Dance
Lv 44 - Guillotine
TMs/HMs it can learn:
TM 03, TM 06, TM 07, TM 10, TM 12, TM 13, TM 14, TM 17, TM 18, TM 21, TM 27,
TM 28, TM 31, TM 32, TM 36, TM 39, TM 40, TM 42, TM 43, TM 44, TM 45, HM 01, HM 03, HM 04, HM 06, and HM 07.
Move Tutor Attacks:
Swords Dance, Body Slam, Double-edge, Counter, Mimic, Substitute, Snore, Icy Wind, Endure, Mud-slap, Swagger, Sleep Talk, and Fury Cutter.
Catch Corphish first and evolve it. And you'll get a crawdaunt
Routes 102, 117, Petal burg City (Super Rod)
Use the good rod on any route you should find it sooner or later.
You need to evolve it from Corphish and to find a corphish you need to go to the route just left of Mauville City and go to where the pond is, surf then fish with super rod. You will easily find a Corphish at around lv30. If you just level him up once, he will evolve.
Go to that route (cant remember which one it is) between Mauville City and Verdanturf Town and go fishing in the pond there. You'll need a Super Rod to get a Corphish.
Same as flygon
mainly water types learn it hope it helped:)
Same as always, level 30. level 30 he evolves into crawdaunt
Crawdaunt are not available in the wild. The only way to get one is to evolve a Corphish (starting at level 30).
It is impossible to make a Pokemon know more that 4 moves in Pokemon Emerald and any Pokemon game. It is hard coded into the games for a Pokemon to never know more than 4 moves. While a Pokemon can learn more than 4 moves it can only know 4 at a time.
Pokemon you can get with the good rod are: TENTACOOL, MARILL, MAGIKARP, CHINCHOU ( under-water ) and CORPHISH.
Hydro Pump,Double Edge,Sheer Cold, and Rest