What is the name of the mode where ghosts are blue and can be eaten?

The mode where Pac-Man’s ghosts turn blue and can be eaten is called Frightened mode.

Pac-Man activates this state by eating a large flashing Power Pellet, also called an energizer. The four ghosts—Blinky, Pinky, Inky, and Clyde—reverse direction, turn blue, and temporarily flee from Pac-Man instead of pursuing him. During this window, Pac-Man can eat them for bonus points.

The bonus doubles with each ghost eaten from the same Power Pellet: 200, 400, 800, and 1,600 points. Afterward, the ghosts flash white to warn that Frightened mode is ending. If Pac-Man eats a ghost, only its eyes return to the center box, where it regenerates before rejoining the chase.

Frightened mode is different from Scatter mode and Chase mode. In Scatter mode, ghosts retreat toward their home corners; in Chase mode, they pursue Pac-Man using distinct movement strategies. The duration of Frightened mode decreases as the player advances, eventually disappearing on later levels.