The leopard does not change his spots

With allusion to jeremiah xiii. 23 (AV) Can the Ethiopian change his skin, or the leopard his spots? A L. equivalent to this proverb is lupus pilum mutat, non mentem, the wolf changes his coat, not his nature.

Their olde condycyons wyll they change, whan the blackemoreæne change hys skynne, and the catte of the mountayne [leopard] her spottes.
[1546 J. Bale First Examination of Anne Askewe 38]

Rage must be withstood. ‥Lions make leopards tame.—Yea, but not change his spots.
[1596 Shakespeare Richard II i. i. 174]

Pardus maculas non deponit, a leopard does not change his spots.
[1869 A. Henderson Latin Proverbs 317]

He always was a dirty old man‥and the leopard doesn't change his spots.
[1979 J. Scott Clutch of Vipers iv.]

Although he swears he has changed, leopards don't usually change their spots, especially those who don't cooperate in counseling.
[1997 Washington Times 24 July C16]

Related to: change; human nature

Bibliography of major proverb collections and works cited from modern editions is available here.