-Required-
To be a Gnome, you must first have the Gnome Dome, that being all you truly require.This is the Gnome Dome, which you can usually find on the community market for around 13 cents USD.
















-Weapons-
Once you have that, the next logical step is the required weapons. The only weapon you'll need for this is the Necro Smasher.
This is the Necro Smasher, which can be unlocked through the achievement Step Right Up.




















-Extras-
As extras, you can wear things like the Pyrovision Goggles or the Flashdance Footies.

Equip the items, then go into a server and A-Pose. Once you have A-Posed, walk around and stare at people, menacingly. Another thing to do is to act as an average friendly by crouching and walking around, doing normal friendly things for that class. And you may only actually fight if you are playing engineer, where you will set up a nest in small spots that will not help your team, but mildly annoy anyone on the opposing team who wants to go there (Ex: A random place with a health pack).