The ornamental design for a body of an electric grass mower, as shown and described.
FIG. 1 is a front perspective view of a body of an electric grass mower in accordance with our new design;
FIG. 2 is a rear perspective view of the body of an electric grass mower in accordance with our new design;
FIG. 3 is a front elevational view of the body of an electric grass mower in accordance with our new design;
FIG. 4 is a rear elevational view of the body of an electric grass mower in accordance with our new design;
FIG. 5 is a top plan view of the body of an electric grass mower in accordance with our new design;
FIG. 6 is a bottom plan view of the body of an electric grass mower in accordance with our new design;
FIG. 7 is a right side elevational view of the body of an electric grass mower in accordance with our new design;
FIG. 8 is a left side elevational view of the body of an electric grass mower in accordance with our new design; and,
FIG. 9 is a front perspective view of the body of an electric grass mower in a state of use.
The broken line showings of the unclaimed portion of the electric grass mower, the attachment and the battery in FIG. 9 are provided for the purpose of illustrating environmental structures; whereas the broken line showing in FIGS. 1-8 illustrate portions of the body of an electric grass mower. These broken line subject matters do not form part of the claimed design.