bridle
post #1820358 post #17179 post #26125
A harness like object put on the head of (mostly) horses in order to direct them. A true bridle also involves a bit going in the mouth and usually attached to reins used for riding or driving.
Albeit there are mechanical differences in uses between real halters and bridles, for the purposes of e621 tagging, a bridle is a halter with a bit gag.