crown of thorns
n//ˌkɹaʊn əv ˈθɔːnz//törnekrona
(Christianity) The crown made of a thorny plant that Christ was forced to wear before his Crucifixion, in mocking reference to his alleged status as ‘king of the Jews’, or a representation of this. [from 10th c.]
Ellipsis of crown-of-thorns starfish [from 20th c.]