A certain rat of a large size that is resistant to regular rat poisons, and may have a voracious or rampant behavior.

plural of superrat

Above or beyond the rational. / Relating to superrationality.

A kind of rational decision-making, different from the widely-accepted game-theoretical one. A player whose opponent is also superrational will cooperate in the Prisoner's dilemma problem, whereas a game-theoretically rational player will defect.

In a superrational manner.