The Canis Major Overdensity is a prominent excess of stars detected just below the Galactic plane in the direction of the Canis Major constellation, interpreted either as a disrupting dwarf galaxy whose tidal debris wraps around the Milky Way or as a manifestation of the warped and flared outer disk (Martin et al. 2004; Momany et al. 2006). In the ΛCDM framework this feature is problematic because its distance, kinematics, and metallicity appear hard to reconcile simultaneously with simple models of a smooth, warp-only Galactic disk, yet invoking a distinct dwarf galaxy progenitor that orbits so close to and within the plane requires fine-tuned geometry and survival times that are not straightforwardly reproduced in standard simulations (Conn et al. 2007; López-Corredoira et al. 2007).