The ornamental design for a collapsiblewagon, as shown and described.
FIG. 1 is a front perspective view of a collapsible wagon comprising a base frame portion, in accordance with one embodiment of the present invention, showing the handle attached to the collapsible wagon is in an extended state (the rear view of the collapsible wagon being a mirror image of the front view, with the collapsible wagon symmetrical about a median between its front and rear sides);
FIG. 2 is a left end perspective view of the collapsible wagon in FIG. 1;
FIG. 3 is a right end perspective view of the collapsible wagon in FIG. 1;
FIG. 4 is a perspective view of the collapsible wagon in FIG. 1, illustrating the handle attached to the left end of the collapsible wagon is in a retracted state, the shelf at the right end of the collapsible wagon folded up, and the collapsible wagon in a transitional state of collapse; and,
FIG. 5 is a front perspective view of the overall frame of the collapsible wagon in FIG. 1, with the flexible basket removed.