Pet coffins and urns. Anyone doing these?

I've been asked to make a concrete coffin for a friend who recently lost her doggie companion of 14 years.
She wants a container that she can remove if she moves so I'm doing a coffin that will actually look much like a stepping stone in her yard. She wants a nice design/picture on the lid that is beyond my ability.
So I suggested she have another artistic friend create the lid mold in a sheet of wax I'll provide and then I will cast the concrete lid from that.

I love casting from wax because it's easy to carve and endlessly reusable.
She has place the wee dog in his bed in a sleeping position in a box in her freezer because she can't bury him until spring.

I'm doing a simple 22" round coffin (like a doggy bed) but making a coffin or urn in the profile of a cat or dog is easy using blue styrofoam. I haven't done it but I have done a maple leaf shaped mold.

If I'm still here when done I'll post a picture. The woman doing the lid carving is very talented, I can hardly wait to see what she brings me to cast.