"I promised I wouldn't tell anyone. that's what Bellatrix Lestrange got sent to Azkaban for, using the Cruciatus Curse on Neville's parents until they lost their minds." Harry, chapter The Order of the Phoenix.
A coffee mug that changes with heat. Sounds like fun :) Magical Coffee Mug super cheap mugs from the dollar store to create gifts or party favors. Just draw on the surface of your mug and bake it for 30 minutes at 350 degrees