Announced as part of X16.2 patch notes on Reddit:
Leprechaun Is Back! (Aug 22nd to Sep 4th)
Sturky
#2
I will still play the Mario 64 Slide theme every time I chase the Leprechaun, it’s just too fitting.
Nevov
#3
Not sure if there was an official word on when they got the bugs fixed, but the Leprechaun Statue is now in the game, he has slightly different behaviour than the old St Patricks Leprechaun.
The statue one starts as a larger size, then gets dmged down to the tiny size (while running around still).
When he gets tiny he goes zooming off again, and then when finally dies, he now drops the pot of gold loot chest directly, no Rainbow Road like earlier in the year.
Sturky
#4
He also speeds up the more you damage him in the stone phase.
Also him sprinting halfway across the entire map Road Runner style is just too much. 2Fast.