Apple
From Tardis Wiki, the free Doctor Who reference
Apples are a common fruit found on Earth. They can be either red, yellow or green. After the Doctor regenerated he wanted an apple but didn't like it. Amelia Pond liked apples ever since since she was young, when her mother would carve faces into them. She gave an apple with a carved happy face on it to the Doctor, who later used it to pacify her older self. (DW: The Eleventh Hour)