Bill and Ben are 24-year-old twin horses.
They live at a horse sanctuary near Cardigan in Wales and they might be the oldest twins in the world!
It's really unusual to get twin horses because it can be dangerous for the mother to give birth to more than one at a time. Bill and Ben are Cremellos and are white with blue eyes.
They used to work at London Zoo giving rides but now they're retired they spend their time relaxing. The Veteran Horse Society looks after 20 elderly horses with different needs.
Guinness World Records are investigating their claim about being the oldest twins. Their stable mate Sugerpuff has a record of her own, for being the world's oldest pony!