Display screen or portion thereof with an animated graphical user interface

The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fees.

FIG. 1 is a front view of a first image of a display screen or portion thereof with an animated graphical user interface showing our new design;

FIG. 2 is a front view of a second image thereof;

FIG. 3 is a front view of a third image thereof;

FIG. 4 is a front view of a fourth image thereof

FIG. 5 is a front view of a fifth image thereof

FIG. 6 is a front view of a sixth image thereof

FIG. 7 is a front view of a seventh image thereof; and,

FIG. 8 is a front view of a eighth image thereof.

The broken lines showing a display screen or portion thereof, electronic device, and other features form no part of the claimed design.