What can I use to write on a terracotta pot?

[PeppaPigStinks]

All in the title really... I have a pot to plant with dd for my mum for Sunday but am looking for suggestions on what I can use to write happy Mother's Day?
Can you help please?

Um... paint a block with a glossy paint and write with a Sharpie type pen?

Personally, I'd probably just make a pretty tag and tie it round the top of the pot with ribbon.

I'd like to tie a card with wishful words to the handle, the card can be saved as a gift in a memorable box.