Cendir's Comments

Actually no, they are found themselves and as adds to a lot of different pets in the zone.

If you don't have the rep for this pet, DO NOT buy it from from Battle Pets tab on the AH, only buy the caged version.  The latter you can learn sans faction, the former you cannot.  Learned this the hard way =/

Duskwood seems by far the best place to find these - they are really common.  They are also unfortunately low level, but if you are looking for a certain breed, I could go there.

It appears these can spawn as an add with anything (or just about anything) in the zone at any time of day.  I saw lots of them as adds to Small Frogs, Skunks, Dusk Spiderlings, Rabbits, etc, between the in-game hours of 11am-6pm.  That is how I got my two rares.

I never saw them spawn on their own, but perhaps THAT is what requires nightfall.

I should imagine people use stones to make them rare.

I got 3 rares as adds while trying for the Scalded Basilisk Hatchlings - the only rares of this I ever saw.  If nothing else, they seem much more common as adds to the Hatchlings than anything else I tried in the zone.

I got this on my 14th cast just 40 ft to the left of the docks.  Not sure it's worth the effort to try and find some special fishing location.