She’s ready? Are you?

Sidesplitting, hysterical, edgy, Tiffany Haddish is one of the most memorable talents of our times.

Growing up in one of the poorest neighborhoods of South Central Los Angeles, Tiffany learned to survive by making people laugh. If she could do that, then her classmates would let her copy their homework and the other foster kids she lived with wouldn’t beat her up. Or at least she could make enough money—as the paid school mascot and in-demand Bar Mitzvah hype woman—to get her hair and nails done, so then she might get a boyfriend.

These early and humble beginnings allowed Tiffany to imagine a place for herself where she could do something she...