If you had half of a brain, you'd definitely enter the Dawn of the Dead Dash, as people with delicious full brains will likely be taken out first. From a Tacoma fitness company, the zombified 3mi race starts at a "quarantined headquarters" for debriefing, where you're given checkpoint clearance cards, a checkpoint location map, and a glow collar to clearly identify you as human/superfan of the movie Fortress.
After you get glowed out, you're sent off on your own with "no set course to take" to get to the next checkpoint. Zombies are released 10 minutes after you saunter out, and will also be hiding throughout the city and near said checkpoints, which will not be terrifying at all as you skulk around all nervous wearing a glow collar. If you do get tagged by a zombie, you're f-ing dead, okay? Give up that glow collar, and then help chase around other people that're so awesome they still have glow collars.
After the race, there will be a "glow collar optional" after-party featuring free Deschutes, so you can go to work on losing the other half of that brain.