The ornamental design for a petexcrementpicker, as shown and described.
1. Pet excrement picker
1.1 : Perspective
1.2 : Perspective
1.3 : Front
1.4 : Back
1.5 : Top
1.6 : Bottom
1.7 : Left
1.8 : Right
1.9 : Cross-sectional
1.10 : Cross-sectional
The portions of the design represented by broken lines are disclaimed; the feature of the claimed design resides in the configuration of the pet excrement picker which is represented by thick solid lines; the shadings indicated by thin lines are only intended to represent the three-dimensional shape of the surfaces of the design.