The ornamental design for a babyteether, as shown and described.
FIG. 1 is a top, front, left, perspective view of a baby teether, showing our new design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a right side elevation view thereof;
FIG. 5 is a left side elevation view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The drawings are shaded to indicate contrasting surfaces. The broken lines in the drawings depict portions of the baby teether that form no part of the claimed design.