I pulled this out of the kiln, and am so pleased with how it turned out that I thought I would share:
I used a plain white porcelain teapot, and added iron oxide decals that I made from a vintage image I found at the Graphics Fairy.
First, I printed the image out onto waterslide paper using my old printer.
I reversed the image for one side so the same tentacles can wrap around each side. It looks great from the front!
I soaked the decals to loosen the backing paper, and placed and smoothed the decals.
After I applied the decals, I fired it to 2050 degrees F. in my electric kiln.
Now the image is permanent, and the teapot (with its image) is dishwasher safe.
And of course, the mugs that match are in my SecondChanceCeramics shop on Etsy.