The Orphan Stream is a long, narrow stellar stream in the Galactic halo whose orbit is strongly tilted with respect to the Galactic disk and appears to lie close to a distinct orbital plane, with distance and velocity measurements tracing a coherent, great-circle–like path whose progenitor dwarf galaxy is now either fully dissolved or only weakly detected (Belokurov et al. 2007; Newberg et al. 2010). In ΛCDM, matching the Orphan Stream’s detailed 3D track, precession, and thickness within a triaxial, clumpy dark-matter halo is challenging, because different halo shapes and subhalo populations that fit other streams (like Sagittarius or GD-1) often mispredict the Orphan Stream’s curvature and kinematics, making it a sensitive and sometimes discordant constraint on the standard Milky Way halo model (Lux et al. 2012; Koposov et al. 2019).