a cloven hoof

cloven hoof

An evil or malicious nature. The devil is typically depicted with cloven hooves. I thought I could trust Eric until he showed the cloven hoof by spreading rumors about me. Jill definitely sabotaged my last two relationships. She might seem nice, but she always shows a cloven hoof eventually.
See also: cloven, hoof
Farlex Dictionary of Idioms.

a cloven hoof

a symbol or indication of evil.
Traditional pictures of the Devil show him with the head and torso of a man but the legs and cloven hoofs of a goat. Therefore, a cloven hoof is a giveaway sign of the Devil.
1959 François Mauriac A Woman of Pharisees She had been a trial to him from the beginning, and now the cloven hoof was beginning to show.
See also: cloven, hoof
Farlex Partner Idioms Dictionary
See also:
  • cloven
  • cloven hoof
  • show the cloven hoof
  • show (one's) horns
  • have to hoof it
  • hoof it
  • not as black as (one) is painted
  • not as black as you are painted
  • painted
  • black as one is painted
References in classic literature
Then the woman has not a cloven hoof for her dairy, or her loom, and I believe even the grunters, foot sore as they be, are ploughing the prairie.
One second later, I was sitting gasping in the dung channel with the neat imprint of a cloven hoof on my shirt front, just over the solar plexus.
"I couldn't believe it - the footprints were in the shape of a cloven hoof. There were no other marks at all in the snow.
Muslims, and my own Jewish religion says: 'Anything to do with a pig is strictly forbidden, only animals with a cloven hoof which chew the cud may be eaten.'
"Unless you have a cloven hoof," says Hays, "you're not going to get this."
Frew retorts that "Murray never said this", that I am putting words into her mouth, and that "There is no mention of a cloven hoof in this section of Murray's book".