A group of kangaroos is occasionally called a court, a far less common alternate to the standard term “mob,” and one that leans more on wordplay than on any documented behavior. It’s hard to separate “court of kangaroos” from the well-known phrase “kangaroo court,” slang for a sham legal proceeding with no real authority, which has been part of English since the 1800s.
The phrase “kangaroo court” itself likely originated in the American frontier and Australian gold rush eras, describing hastily assembled, informal, and often unjust tribunals, possibly a nod to how quickly, and erratically, such proceedings could jump to conclusions, not unlike a kangaroo’s bounding hop. “Court of kangaroos” as a collective noun feels like a cheeky nod back to that phrase rather than a genuine field observation.
Bonus fact: kangaroos can’t walk backward. Their large feet and tendon structure are built almost entirely for forward hopping, which is part of why the kangaroo appears on Australia’s coat of arms, as a symbol of a nation that only moves forward.
For everyday and biological accuracy, “mob” remains the far more widely used and documented term for a kangaroo group.
Related: Collective Nouns for Mammals · What Is a Group of Kangaroo Called? · A Mob of Kangaroos