The ornamental design for a tillerhead, as shown and described.
FIG. 1 is a perspective view of a tiller head showing my new design;
FIG. 2 is a front view of the tiller head of FIG. 1;
FIG. 3 is a side view of the tiller head of FIG. 1;
FIG. 4 is a top view of the tiller head of FIG. 1; and,
FIG. 5 is a bottom view of the tiller head of FIG. 1.
The broken line showing of portions of the tiller head and a shaft is included for the purpose of illustrating environmental structure and forms no part of the claimed design.