Lippisch DM-1. This was a full scale test glider to test the design that was to be used in the Lippisch P.13a ramjet-powered interceptor. Captured by the US, it was used as
Lippisch DM-1(Huma) | ModelPlanes.de
Lippisch DM1 | Hazy, Aircraft, Steven
Lippisch DM-1 by Piotr Dmitruk (Huma 1/72)
Lippisch DM-1 and subsequent NACA redesign | Secret Projects Forum
Lippisch DM-1 "Flying Triangle" - Gliders and Motor-Gliders - X-Plane.Org Forum
Lippisch DM 1 Reconsidered - Part 4 | National Air and Space Museum