White Elephant

The often-repeated story holds that the kings of Siam would gift a rare, sacred albino elephant to a courtier who had fallen out of favour. The animal couldn't be worked or killed, since it was considered sacred, but it was ruinously expensive to feed and house, making it a beautiful, deliberately punishing burden disguised as an honour. The phrase enters documented English usage from 1851, and the Siamese custom is repeated across many reputable phrase histories, but no single verified historical instance of a king actually doing this has ever been pinned down.