I am certain I will never get the 20 pets or the single pet achievement. Trying to get one for posting though.

Actually, I have to add on Hoarding... UUG, Hoarding is HARD!

for me I think the Legendary Merger

Item Hunt Searcher Hustler (UGH! -- He hates me!) Edward! (I've never been able to find it in the Crystal Shop) Fishing Master and Random Champion

LOL ... I could go on and on!