How to describe Eeyore's Birthday Party? Officially, it's a free-admission outdoor party and fundraiser for Austin nonprofit groups. Historically, it's a weird, far-out way to turn your weekend into a blur. Whatever it is to you, it's happening 11 a.m. to dusk Saturday at Pease District Park.

The No. 1 thing to remember about Eeyore's Birthday Party: You wear a costume. You just do, even if that costume does not include a top. The party website promises costume contests, as well as face painting, henna and temporary tattoos and more to help you "become the avatar" you want to be. Food vendors will be on site. Musicians are encouraged to bring and play their non-amplified instruments. Drum circles? That's pretty much a key feature of this shindig.

» FROM THE ARCHIVE: Happy 50th to Eeyore’s Birthday Party

Speaking of music, live performers on the stage include Black and White Years, Warren Moon Band, Tex Offenders and more. The jams start at noon.

Watch for maypoles, too. Check eeyores.org for more information, including possible rain delay or cancellation plans.