dog egg

noun2

1. •
   (slang, vulgar) A lump of dog faeces.

   • For the first time a musical collector ‘dog’s egg’ created in the opulent Faberge tradition, capturing magnificently the magic of a fouled footpath. — 1997
2. •
   (vulgar, offensive) A worthless or contemptible thing or person.

   • You can smile and open your eyes wide and look as though you are showering the recipient with praise, but what you’re actually saying is, “You are a dog egg.” — 2014