Miranda sent in this unusual planter. I used to have one back in the days when my husband and I had an antique mall, and we never found out who the maker was so we eventually sold it. Later we found that it might be Weller. I thought I had seen it in one of the books, but we just looked through and it's not in the one we have. However, I was able to find a discussion on an eBay forum that also says it's Weller. The patent is actually for the shape, not for the pottery piece itself. The patent was in the name of an Arthur Lindwall in 1940, so the piece dates sometime after that. See for patent details.
Link to eBay forum discussing the three-headed dog
Patent for the shape
