It is questionable whether this is really a coprolite. It is an interesting rock nevertheless. Can you see the shape of a puppy dog?
Many rocks are sold online are said to be coprolites. These rocks are primarily made up of silica (aka siliceous). However, without identifiable inclusions or backfilled burrows left by coprophagous (poop-eating) insects such as dung beetles, it is impossible to determine if these are geological or really do have fecal origins.