Billy wrote:

I have a ceramic pot that looks to be about ten gallons in size and it
doesn't have a drain hole at the bottom.

Do not attempt to do this job with a large masonary drill, almost
guaranteed to FIU.

Search tungston carbide grit hole saw.

http://www.holesaws.com.cn/products/...aw/gritsaw.htm

http://www.mytoolstore.com/mkmorse/tcg.html

With pottery use the small pilot hole to cut from both sides.