Avoir des oursins dans la poche

Literally: To have sea urchins in one's pocket

Example: “Il ne paie jamais sa tournée ; il a des oursins dans la poche.” — He never pays for a round; he's a real penny pincher.

English equivalent: A penny pincher

Origin: The picture explains itself, and the word has a small puzzle of its own: oursin, from the middle of the 16th century, is taken by some as a deformation of ourson, a bear cub, and by others from the Occitan orsin de mar. The creature — also called hérisson de mer, sea hedgehog, and châtaigne de mer, sea chestnut — is covered in spines that nobody wants to drive into a finger. A man with a pocketful of them would very sensibly leave his hand out of it, and to anyone unaware of what he is keeping in there, that reluctance to reach for his money looks exactly like meanness.