Granny is a title unlocked by purchasing the "Farm deeds (+titles)" reward for 250,000 beans in the Farmers' Market. The reward also unlocks the the Master Farmer, Potterington, and Grandpa/Grandma titles.
This title changes according to the language of the server on which RuneScape is played, as shown below:
||Vovô [Name] / Vovó [Name]
|This information has been compiled as part of the update history project. Some updates may not be included - see here for how to help out!