tubb, i got all the 2 leg ones in the area around the lodge. just say in that area, walk around the entire area a couple of times. kill the one or maybe two that show up, save quit and do again. no clue on the albino skags though
Pink Boraks - Hunter's Grotto, either up the elevator area where you have to open a gate to get to or the Southern part of the map is where I found the most of them, though I think they can also spawn at the Ardorton Station.
Tailless Scaylions - These can spawn in quite a few places, but where I found the most tends to be in the area where you have to fight the named one for part of the main quest at Scylla's Cove, though I'd imagine they can be also found at Candlerakks Crag or Ardorton Station.
Two-Legged Drifters - As someone else stated, I found these after you kill a few normal drifters around the lodge area.
Albino Skags - I think most, if not all of these were in the area where the first skag pee quest was in Scylla's Cove.
Slag Spores - Hunter's Grotto is where I found all 4. --- I am Alpha and Omega, the beginning and the end.