Hypothesizzle

• WWizards of the Coast2024-04-12
  Official Ruling
  You don't choose a target creature at the time you cast Hypothesizzle. Rather, a second "reflexive" ability triggers when you discard a nonland card. You choose a target for that ability as it goes on the stack. Each player may respond to this triggered ability as normal. Notably, the triggered ability isn't a crime, but the reflexive triggered ability potentially is.

Rulings via Scryfall