Described is a portable bed for outdoor use by a dog or other large pet which is movement-resistant when placed on a ferromagnetic surface such as a truck bed. The bed includes a durable removable outer cover suitable for exposure to inclement weather and an inner cushioning element received within the outer cover which may be a dog bed suitable for indoor use. At least a portion of the outer cover comprises a material producing a sufficiently strong magnetic field to impede or prevent the bed from shifting or otherwise moving on the ferromagnetic surface. This may prevent or at least measurably reduce shifting or other movement of the portable dog bed in a truck bed when the vehicle accelerates, breaks or turns. Alternatively, the portable bed may be configured for use as an insert in a dog crate with an optional top spill pad for convenient removal and cleaning.