FIG. 1 is a perspective view of a combined portable pet stair and carrying bag, showing my new design;

FIG. 2 is a perspective view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a side elevation view thereof;

FIG. 5 is a front elevation view thereof;

FIG. 6 is a rear elevation view thereof; and,

FIG. 7 is a perspective view of the inner-core portion of FIGS. 1-6.

The broken lines in FIGS. 1 and 2 are for purposes of illustration only and form no part of the claimed design.