Whimsyshire? Whimsydale? Two mysterious pony filled lands you can explore in Diablo 3
Some thoughts and data after killing 100 Rainbows - General Discussion - Diablo 3 Forums
Princess Stardust [Whimsydale] : r/diablo3
First rainbow goblin after transmogging my DH to look like Goblin Slayer yielded results. Highly suggest doing so as a legitimate farming strat : r/ Diablo