The giant blob, as always, appears at random times. Usually every 3-4 hours, in my experience, though I have seen it appear twice in half that time.
It's truly random. Chill out in that strangely loot free puddle near the witch's house for a couple hours or slash some grass in the surrounding area for the same and you'll probably run into the blob.
My question is what are the items available?
Do you get the bombs/mounts/pet/hats from before, or is it new stuff now?
So far this year I got one hat that looks like it should have been on the cutting room floor... so haven't been spending too much time worrying about mr blob,
seeing as though I have 2 mounts, bomb, pet, and a bunch of hats from before.