From Entertainment Earth:

The whimsical tree known as Groot can say “I am mug!” next time someone asks! This Guardians of the Galaxy Smiling Groot Molded Mug features the expertly crafted likeness of actor Vin Diesel’s heroic tree-creature. Hand wash only. Not dishwasher safe. Do not microwave.

[Pre-Order: Guardians of the Galaxy Smiling Groot Molded Mug]