The ornamental design for a disposable splattershield, as shown and described.
FIG. 1 is a left top oblique view of a disposable splatter shield showing my new design;
FIG. 2 is a right top oblique view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a bottom plan view thereof;
FIG. 5 is a front plan view thereof;
FIG. 6 is a rear plan view thereof;
FIG. 7 is a left plan view thereof; and,
FIG. 8 is a right plan view thereof.
The broken lines shown in the figures are included for the purpose of illustrating portions of the disposable splatter shield and form no part of the claimed design.