Rule 710.1 · Flip Cards
Flip cards have a two-part card frame on a single card. The text that appears right side up on the card defines the card’s normal characteristics. Additional alternative characteristics appear upside down on the card. The back of a flip card is the normal Magic card back.
Subrules
The top half of a flip card contains the card’s normal name, text box, type line, power, and toughness. The text box usually contains an ability that causes the permanent to “flip” if certain conditions are met.
The bottom half of a flip card contains an alternative name, text box, type line, power, and toughness. These characteristics are used only if the permanent is on the battlefield and only if the permanent is flipped.
A flip card’s color and mana cost don’t change if the permanent is flipped. Also, any changes to it by external effects will still apply.