A leash attachable animal excrement bag holder has a carabineer for engaging a leash, body-supported apparel or the like, a flexible, resilient and open-biased support hoop, and a bag suspended from the support hoop. A slide has a body and first and second holes passing entirely through. The first hole encompasses the support hoop at a first distinct location and the second hole encompasses the support hoop at a second distinct location. The slide operatively traverses the support hoop and thereby alters a bias of the support hoop from an open orientation suitable to receive or remove animal excrement bags to a more nearly closed orientation suitable to retain animal excrement bags. A coupling engages the support hoop with the carabineer.