All gnomes are fairly eccentric; their lives in the underworld have exposed them to much strangeness.
Deep Gnomes, who live far, far below the surface, are extremely eccentric, and obsessed with building and tinkering with fantastical — and dangerous — machines. Their ruler is Azbqiplth, Lord of the Deep Gnomes.
Gnomes love to play games. Their games rarely make sense to non-gnomes and sometimes involve people getting injured or killed. The Owl Bear Game is a great example.
The Gnomish National Anthem is very, very long.