  We have studied the shadows of black hole immersed in Melvin magnetic field.
Due to the existence of Melvin magnetic field, the shadow of
Melvin-Schwarzschild black hole becomes more elongated in the horizontal
direction so that the black silhouette changes from a perfect circle to an
ellipse. We also present the change of the eccentricity for the ellipse-shaped
shadow with the magnetic field parameter. For a rotating black hole, with the
increasing of the rotation parameter, the ellipse-shaped shadow becomes
gradually a D-shaped silhouette elongated in the horizontal direction.
Moreover, the right part of the D-shaped and elongated shadow boundary can be
matched very well by a part of an ellipse, and the corresponding eccentricity
decreases with the rotation parameter and increases with the magnetic field
parameter. In addition, there also exist some self-similar fractal structures
in the shadow of Melvin-Kerr black hole arising from the chaotic motion of
photon. These behavior of shadow of Melvin-Kerr black hole can help us to
understand the black hole shadow and the magnetic field around black hole.
