Display screen or portion thereof with an animated graphical user interface

[0001]FIG. 1 is a front view of a first image in a sequence of a display screen or portion thereof with an animated graphical user interface;

[0002]FIG. 2 is a front view of a second image; and,

[0003]FIG. 3 is a front view of a third image thereof.

[0004]The outermost broken lines in the FIGURES illustrate the display screen or portion thereof and form no part of the claimed design. The other broken lines in the FIGURES show portions of the graphical user interface that form no part of the claimed design. The appearance of the display screen or portion thereof with an animated graphical user interface transitions sequentially between the views shown in FIGS. 1, 2, and 3 respectively. The process or period in which one FIGURE transitions to another forms no part of the claimed design.