As title says. I always feel like Menagerist Goblins are lacking in rewards once you have the full cosmetics from them. I played this game for a long time and there’s nothing left for them to offer an old player like me. When I see them, they’re not really different than a Treasure Goblin loot-wise for me. Any other goblin have their distinctive loot and traits while Menagerist falls short and everyone complain about key farming to the point of being fixated on useless ideas.
So I come up with this; make Menagerist Goblin have a chance to drop one Greater Rift key at high Torment difficulties such as T10 and above. Scaling can start with 25% at T10 and each additional difficulty level above T10 adding 3% chance; it will top at 40% at T16. In case your Follower wearing Cain’s Set, then you will walk away with 2 Greater Rift keys from this deal at most.
With their rather low spawn rate, it won’t make a noticable impact. If their spawn rate is rather high for this sort of reward, it can be easily tweaked down as well. This way it will be a nice boost for key farming while doing bounties.
Also since Menagerist Goblins only can grant a total of 2 Greater Rift keys at T16 per encounter, that doesn’t encourage anyone to rabidly look for them when they can run a proper Nephalem Rift and stack them faster.