“Those who say there’s nothing like a nice cup of tea for calming the nerves never had real tea. It’s like a syringe of adrenaline straight to the heart!”
-Cheshire Cat

The Cheshire Cat is a fictional cat popularized by Lewis Carroll in Alice’s Adventures in Wonderland and known for its distinctive mischievous grin. While now most often used in Alice-related contexts, the association of a “Cheshire cat” with grinning predates the 1865 book.

Wikipedia