What is the name of the super-powered baby in The Incredibles?

The super-powered baby in The Incredibles is Jack-Jack.

Jack-Jack Parr is the youngest child of Bob Parr, also known as Mr. Incredible, and Helen Parr, also known as Elastigirl. His older siblings are Violet and Dash, whose powers are invisibility and super-speed. For much of the first film, Jack-Jack appears to be the only Parr family member without abilities.

That assumption collapses near the end of The Incredibles, when Jack-Jack demonstrates several powers while Syndrome attempts to kidnap him. His abilities include shapeshifting, teleportation, levitation, fiery transformation, and the ability to pass through solid objects. The short film Jack-Jack Attack reveals still more of his unpredictable powers.

A common mix-up is confusing Jack-Jack with Dash, the other young Parr known for super-speed. Jack-Jack's name is a nickname for John Jackson Parr, and Incredibles 2 expands his role by showing that his powers continue developing.