The ornamental design for the chum dispenser, as shown and described.
FIG. 1 is a front elevational view of the chum dispenser in accordance with the present invention, the opposite side being a mirror image thereof and the left and right views being mirror images thereof;
FIG. 2 is a top view thereof;
FIG. 3 is a bottom view thereof; and,
FIG. 4 is a perspective view of the chum dispenser in condition of use as secured to a sea vessel in a body of water and suspending a net that holds chum.
The broken lines are for environmental purposes only and form no part of the claimed design.