Oktoberfest

The Oktoberfest will be an event in the month October.

Currently there is a guy named Pretzel Bert just east of Varrock, he appears to be selling pretzels but he asks you to come back later.

Also in the Quickchat you are able to find a new holiday item named Oktoberfest Pretzel.

In order to get this just type in the quickchat search option: I got an item. and click on that and then type in oktoberfest pretzel.

your character will then say: I got an item: Oktoberfest pretzel.

This is most likely the reward for the event.