A leopard cannot change its spots means people do not really alter their nature. Well, a leopard cannot change its spots, they say a leopard cannot change its spots.
It is always said with resignation and usually after somebody has disappointed for the second time. The line comes from the book of Jeremiah, which asks the question rather than stating it.
1phrasea leopard cannot change its spotsPeople do not really alter their nature.
“Mum thinks he's reformed, but I've always said a leopard cannot change its spots.”
a leopard cannot change its spots is a saying.
From a question in the book of Jeremiah about whether a leopard can change its spots.
Ultimately from Jeremiah 13:23.
Etymology from Wiktionary, CC BY-SA
Practised in Idioms