As title
I think it should be added to the dog pet with the skill on fetch.
When you are using bloodmagic the fairy heal is very nice.
When you want more chance on items the imp is nice.
For fetch at first I was thinking if it also gets any items that drop or it should add on pickup radius.
But I think fetch was boosted on the new patch not really sure but I feel it gets more gold now.
Yes, and I think it should be a pet squirrel! Then it can stash them away in your special bags for them for winter. 
How about making them loot 10-15 normal crystal and give us rare crystal and up. lol… i think this is good since we need all crystal normal rare and ultra rare. so i think this is balance since it only focus on 1 or 2 tier crystal to get. that make we still need to change pet for another farming. beside pet now cant be buy. neex to look for it. and probably make that kind of pet rarely on enslaver haha