Does exactly what it says on the the tin/mug.

These are Hercules Morse Mugs which are capable of acting as a vessel for such liquids as:

Tea Coffee Hot Chocolate

The adventurous amongst you may even dare try more viscous substances such as:

Baked Beans Baked Beans with Sausages Baked Beans with Sausages and Hot Chocolate

You'd be a mug not to get one.*

*Please excuse this puerile attempt at humour.