One That Didn't Get Away

Are you missing this achievement? You are too lazy to fish for hours?

Fear not! For there is an easy solution.

Fish in Andorhal inside the Deaths of Chromie scenario. For some reason the chance to fish a rare catfish is extremely high.
I used my artifact rod (it completely maxes out during the scenario).

Proof: http://i.imgur.com/nvDDCow.png ("X-pfündiger Wels" is german for X pound catfish)

Enjoy.

EDIT: For what am I getting downvoted? It is true

This is what I got when fishing for 15 Pound Mud Snapper, for the achievement:

Fishing at Stonebull Lake in Mulgore at Loc: 44.3, 61.1 (Just in front of the Fishing Trainer, Uthan Stillwater)

Skill: 375+27 (402)

670 casts:

Brilliant Smallfish - 411 caught: 61.3% drop rate
Longjaw Mud Snapper - 250 caught: 37.3% drop rate
10 Pound Mud Snapper - 5 caught: 0.7% drop rate
12 Pound Mud Snapper - 1 caught: 0.1% drop rate
Minor Healing Potion - 1 caught: 0.1% drop rate
Minor Mana Potion - 1 caught: 0.1% drop rate
15 Pound Mud Snapper - 1 caught: 0.1% drop rate

Note that the drop rates are far from exact, since I didn't have a massive amount of casts.

(Thanks to El's Extreme Anglin' for pointing me towards Stonebull Lake)

Theres something about One That Didn't Get Away achievement.

• 
  
• 103 Pound Mightfish

Caught from:
- Azshara (Bay of Storms, Hetaera's Clutch and Scalebeard's Cave only)

Minimum skill to cast: 330
Minimum skill to avoid get aways: 425
Catch Rate: <1%

• 22 Pound Lobster

Caught from:
- Azshara (Bay of Storms, Hetaera's Clutch and Scalebeard's Cave only)

Minimum skill to cast: 330
Minimum skill to avoid get aways: 425
Catch Rate: <1%

• 32 Pound Catfish

Caught from:
- The Barrens
- The Wailing Caverns
- Blackfathom Deeps
- Silverpine Forest
- Undercity
- Bloodmyst Isle (except unnamed inland areas and The Foul Pool)
- Darnassus
- The Deadmines
- Ghostlands (except Southern Lakes)
- Ironforge
- Orgrimmar
- Stormwind City
- Thunder Bluff
- Westfall
- Darkshore
- Loch Modan

Minimum skill to cast: 1
Minimum skill to avoid get aways: 75
Catch rate: <1%

- Ashenvale
- Duskwood
- Hillsbrad Foothills
- Redridge Mountains
- Stonetalon Mountains (except Blackwolf River and Cragpool Lake)
- Wetlands

Minimum skill to cast: 55
Minimum skill to avoid get aways: 150
Catch rate: <1%

- Alterac Mountains
- Arathi Highlands
- Desolace
- Dustwallow Marsh
- Scarlet Monastery
- Stranglethorn Vale
- Swamp of Sorrows
- Thousand Needles

Minimum skill to cast: 130
Minimum skill to avoid get aways: 225
Catch rate: <1%

• 68 Pound Grouper

Caught from:
- Azshara (except Bay of Storms area)
- Feralas
- The Hinterlands
- Stranglethorn Vale (Jaguero Isle only)
- Tanaris

Minimum skill to cast: 205
Minimum skill to avoid get aways: 300
Catch rate: <1%

• Rockhide Strongfish

Notes: Can only be caught during the Stranglethorn Fishing Extravaganza.

Time: Sundays 14:00-16:00 only.

Commentary: Ultra-rare catch from Schools of Tastyfish during the Stranglethorn Fishing Extravaganza. Unlike the other rare fish, there is no quest involved - just equip the fish as a weapon. The Rockhide Strongfish is the rarest of all contest fish - estimated at less than 1 in 1000 catches. Most anglers will never catch it.

Minimum skill to cast: 130
Minimum skill to avoid get aways: 225
Catch rate: Infrequent catch.

• 15 Pound Mud Snapper

Caught from:
- Azuremyst Isle (Ammen Vale Lakes)
- Dun Morogh
- Durotar
- Elwynn Forest
- Eversong Woods (except unnamed inland areas)
- Mulgore
- Teldrassil
- Trisfal Glades

Minimum skill to cast: 1
Minimum skill to avoid get aways: 25~
Catch rate: <1%

• 29 Pound Salmon

Caught from:
- Burning Steppes
- Eastern Plaguelands
- Feralas (Jademir Lake only)
- Scholomance
- Silithus
- Stratholme
- Winterspring
- Zul'Gurub

Minimum skill to cast: 330
Minimum skill to avoid get aways: 425
Catch rate: <1%

• 52 Pound Redgill

Caught from:
- Azshara
- Felwood
- Feralas (except Jademir Lake)
- The Hinterlands
- Maraudon
- Moonglade
- The Temple of Atal'Hakkar
- Un'Goro Crater (except Fire Plume Ridge)
- Western Plaguelands

Minimum skill to cast: 205
Minimum skill to avoid get aways: 300
Catch rate: <1%

• Dark Herring

Caught from:
- Howling Fjord (Fangtooth Herring School)
- Grizzly Hills

Minimum skill to cast: 380
Minimum skill to avoid get aways: 475
Catch rate: <1%

• Steelscale Crushfish

Caught from:
- Ashenvale
- Hillsbrad Foothills
- Wetlands

Minimum skill to cast: 55
Minimum skill to avoid get aways: 150
Catch rate: <1%

Source