The ornamental design for a markingtoy, as shown and described.
FIG. 1 is a top front perspective view of a marking toy showing my new design;
FIG. 2 is an enlarged scale rear end view, shown without the broken line elements at the front end in FIG. 1;
FIG. 3 is the front end view opposite to FIG. 2;
FIG. 4 is a bottom view shown on a reduced scale relative to FIGS. 2 and 3;
FIG. 5 is the top view opposite to FIG. 4; and,
FIG. 6 is the side elevational view.
The broken lines are included for the purpose of illustrating portions of the marking toy and/or environmental structure that form no part of the claimed design.