Image by Cmglee, CC BY-SA 4.0, via Wikimedia Commons
A square can tile a plane but can form a repeating pattern. Is there a single shape that can tile but never repeats? That's what's called the "einstein problem".
In 2010, the first never-repeating tile was discovered: the Socolar-Taylor tile. But it's a bit weird, having several separated, disconnected bits.
In 2022, "The Hat" (shown in pic) was discovered, and it's a lot less weird. It only has 13 sides and nice angles that are multiples of 30°.
