Improved tissue fasteners are disclosed that can be inserted into (and optionally through) tissue structures underlying a tissue surface for affixing overlapping tissues and tissue planes together, and the like. In some embodiments, an elongate anvil body may protrude distally and/or laterally from a fastener support disposed along the base. The anvil body may have a sharpened end and be configured to penetrate into the tissue, with the elongate anvil body optionally having a bend from a more distal orientation adjacent the clip support to a more lateral orientation adjacent the sharpened end during at least a portion of the deployment. The first leg can be driven through a desired location on the surface of the first tissue and against a receptacle of the anvil body so as to deform the fastener and affix it to the first tissue.