It is likely (but not yet confirmed) that this achievement can be complete alone at level 70.
I was able to solo this achievement on my 70 ret pally. I had previously completed the "Nat's Measuring Tape" quest, so was able to buy a Mudskunk Lure from Nat Pagle before entering Zul'Gurub.
Once in the instance, you can immediately make your to the left -- being careful to avoid the two groups of axe-throwers -- and jump off the cliff into the water. The Hooktooth Frenzies were not much trouble at all for me, but you can avoid them using Elixir of Water Walking.
Elixirs of Water Walking also makes it easier to fish from pools of Muddy Churning Water because you can fish while standing on the water instead of the edge of the shore near the crocolisks (however, the groups of crocolisks were no match for a well geared ret pally).
Once you have the requisite number of Mudskunks, you just head on over to Pagle's Point, right click on the Mudskunk Lure, and bingo! Achievement, er, well, uh, achieved.
It takes a while for Gahz'ranka to make his way out of the water, so you may be able to hearth out if you're lucky.
