Shitter

In gacha comunity, a person who has unspeakable luck. Like in a game with a 300 pull pity, getting 2-3 copies of the featured unit in the first 10 pull. Or pulling a char with a single free ticket.
An act of being a shitter is also called: "shittering"

Person1: "Omg, I got her on my first pull. Kek "
Person2: "Shitter!"

alt. "shittering"
- "I shittered the OG Artoria on a recent banner. I still can't believe it!" (Artoria is well kown character from a gacha Fate/Grand Order)