With Greed’s Domain now on the live servers, Treasure Goblin farming has become a thing. There’s nothing special to be seen about the goblins that open the portal to Greed, it’s just that sometimes one will open a yellow portal when it dies. (Alas, there’s apparently no benefit to allowing the goblin to almost escape so it opens up the portal on its own.)
This week’s double goblin bonus event should help, but what really helps is knowing where to find Goblins in the first place. Currently, the only known game area with a goblin (almost) every time is the Act One Halls of Agony level 2. Just get into Adventure Mode and flash through that level each game, and sooner or later one of the goblins will be the lucky one. (PTR testing got a Greed’s Domain portal about every 1/20 or 1/25 goblins, though that probability hasn’t been confirmed on LIVE yet).
Something that is new on live in Patch 2.1… rainbow goblins leading to Whimsyshire! Obviously inspired by (or those were inspired from the game idea?) those merch-tastic rainbow goblin plushies, some fans have encountered ultra-rare rainbow treasure goblins who open a portal not to Greed’s Domain, but to Whimsyshire (though the portal says “Whimsydale”, oddly enough).
Sadly, it’s just the usual Whimsyshire, just as if you’d entered it via the ghost cow on the way to Old Tristram. It’s not a goblin-filled Whimsyshire rainbow land, or a rainbow-themed Greed’s Domain. Still, it’s kind of a cool Easter Egg and is certainly an Undocumented Patch 2.1 Feature, so good hunting.
Update: Blizzard commented on the name change, from “shire” to “dale.”
Not really no… Whimsydale is pretty much identical to Whimsyshire. The only difference between the two is the name, which had to be changed behind the scenes in order to get the portal to work correctly.