What animal takes part in Schrödinger's most famous thought experiment?

The story behind the answer

Cat is correct. In Schrödinger’s 1935 thought experiment, a sealed box contains a radioactive atom linked to a poison vial; if the atom decays, the poison is released. Quantum mechanics says the atom can be in a superposition of decayed and not decayed, implying the cat is both dead and alive until an observation “collapses” the state.

Schrödinger proposed this to critique the Copenhagen interpretation and highlight the measurement problem—how quantum possibilities become a single outcome. No real cat was involved;