The ornamental design for a petburial or cremationbag, as shown and described.
FIG. 1 is a plan view of my new design for a pet burial or cremation bag, in an open, unfolded first configuration;
FIG. 2 is plan view of my new design, in a part closed second configuration;
FIG. 3 is an upper perspective view of my new design, in a part closed third configuration;
FIG. 4 is a plan view of my new design, in a part closed fourth configuration;
FIG. 5 is a plan view of my new design, in a part closed fifth configuration; and,
FIG. 6 is a plan view of my new design, in a closed sixth configuration.
The features shown in broken lines are for illustrative purposes only and form no part of the claimed Design. No claim is made to texture, surface finish, or surface ornamentation.