Fjord Rat
Source: Pet Battle. If not for being extremely accident prone, the fjord rat might take over the world. Critter type. South of Utgarde Keep. The key to getting the battle pets to spawn is to kill all the regular fjord rats running around.
The Fjord Rat is a wild battle pet found in Howling Fjord, Northrend, caught by killing regular fjord rats to trigger battle pet spawns.
Guide awaiting review
Travel to Howling Fjord
Head to Howling Fjord in Northrend and make your way south of Utgarde Keep, where fjord rats roam the area.
Kill Regular Fjord Rats
Killing the regular (non-battle) fjord rats causes more to spawn rapidly, and green paw icons will begin appearing, indicating battle pet versions are now present.
Watch for Daggercap Hawks
Near Wyrm Skull Village, Daggercap Hawks can engage and kill the Fjord Rat during a battle, so deal with any nearby hawks before starting a pet battle.
Horde Players Avoid South
If playing as Horde, avoid wandering too far south of the hunting area, as the nearby Alliance town will flag you for PvP.
Try Catching as Secondary
If a wild Fjord Rat does not appear directly, the Fjord Rat can also be caught as a secondary pet in battles against other Howling Fjord wild pets, though it may take several attempts due to the variety of secondary pets in the zone.