The ornamental design for a claypigeon, as shown and described.
1. Clay pigeon
1.1 : Perspective
1.2 : Top
1.3 : Left
1.4 : Bottom
1.5 : Perspective
1.6 : Top
1.7 : Left
Views 1.1 to 1.4 illustrate the clay pigeon in an unilluminated state and views 1.5 to 1.7 illustrate the clay pigeon in an illuminated state; features shown in even broken lines do not form part of the claimed design, and are shown for context only; the radial lines around the boundary of the clay pigeon in views 1.5 to 1.7 illustrate emission of light from the surface of the clay pigeon and show the clay pigeon is lit; the radial lines themselves form no part of the claimed design.