According to the Varrock Census in the library, the name of the Varrock town crier is Gryff Aldock.
Players can know they are near one if they have sound on by the bell ring they make.
When a player moderator in-game talks to a town crier, they have access to a few more questions to ask him. These are likely to be player moderator-related questions.
The Town crier in East Ardougne is one of the NPCs you can start the Ardougne Tasks by talking to, and will give you the Ardougne cloak 2 as a reward for completing the medium tasks. If you lose the cloak, you can talk to him for another.
The town crier also seems to be one of the few NPCs who is aware that RuneScape is a "computer game," as he says "...go to the website for more information." This is an example of a character "breaking the fourth wall".