The ornamental design for a discoballnoveltyheadwear, as shown and described.
FIG. 1 is a front elevation view of the disco ball novelty headwear showing my new design.
FIG. 2 is a top plan view of the design of FIG. 1.
FIG. 3 is a left side elevation view of the design of FIG. 1.
FIG. 4 is a right side elevation view of the design of FIG. 1.
FIG. 5 is a rear elevation view of the design of FIG. 1; and,
FIG. 6 is a bottom plan view of the design of FIG. 1.
The human head shown in broken lines in FIG. 3 forms no part of the claimed design and is included to illustrate the environment in which the design is used and assists in showing how the claimed design appears when worn.