A connector for an animal has a stopper mechanism for enabling or disabling a slide bar to be pushed back. The connector for an animal includes a hook member a stem portion extending from an end of the hook member in a first direction a slide bar for being reciprocated in the first direction to open or close the hook member a lock member for being installed around the stem portion to rotate therearound with the first direction as a rotation axis and an operating member for being connected to the slide bar so as to protrude in a second direction perpendicular to the first direction, the lock member including a cylindrical member with a cylindrical space formed therein for housing the stem portion rotatably and projection extending from a part of the hook member side end of the cylindrical member toward the hook member by a predetermined length.
