Since v2.2 went live this week, I’ve seen a lot of complaints about one of the new Treasure Goblin types, the Gelatinous Sire. Lots of players say they’re bugged, that they don’t drop anything when you kill them or that they don’t split into smaller versions of themselves. It’s entirely possible that there are some bugs, and lots of players say if you kill them too quickly they won’t split.
That said… I saw a bunch of these on the PTR and they all worked as designed, no matter how fast I killed them. The first stage is the Gelatinous Sire, which is a normal-sized goblin that’s transparent blue in color. When you kill that one, no items drop and it will split into two (or three?) smaller Gelatinous Spawn which move away quickly. Those drop nothing but gold coins as they run, and when killed they split again, into two or three very tiny Gelatinous Spawns. Those third stage Spawn are what drop items when killed, and they drop about the same amount of stuff as a normal goblin, but with a higher chance of legendaries.
It’s possible there are bugs, but it’s also possible that some of the the tiny, light-blue, slightly-transparent Goblins are just getting away in the chaos of battle. See the attached pics and note how tiny they are by the third stage of the Gelatinous Spawn, easily smaller than any other targetable monsters in the game, and those are what you have to kill to get items to drop.
Gelatinous Sire: Bugged or just Tricky?