Mona Lisa is a famous painting that came to life when the planets aligned. She appears in the episode So in Louvre are we two.
When Muriel was little, her mother said she looked like the Mona Lisa; Muriel brings this up when she goes to Louvre with Courage. This night, however, is a night where the planets align and bring the paintings to life. Mona Lisa is in love with the Thinker, but he rejects her. Courage eventually makes the Thinker realize his feelings for Mona Lisa and the two go out on a date.
- The "Mona Lisa" is a portrait by the Italian artist Leonardo Da Vinci. Just like in this episode, she can be found at the Louvre in France.
- In The Transplant, Courage painted the Mona Lisa as part of a contest with Eustace.
- Unlike most of the animated art characters in the museum, like The Thinker, she speaks with an accent, which is Italian. This is because da Vinci actually painted the iconic portrait from a real life Italian woman identified as Lisa Gherardini (a.k.a. Lisa del Giacondo).