'Supernatural's' Misha Collins is inspiring people around the world with a wacky scavenger hunt

"Supernatural" star Misha Collins has been inspiring people all over the world with GISHWHES, or Greatest International Scavenger Hunt the World Has Ever Seen.

GISHWHES 2015 takes place from August 1-8 and today (Tuesday) is the last day to sign up.

Tens of thousands of people from more than 100 countries have participated in GISHWHES over the last few years.

Participants are tasked with earning points by performing challenges or "items" ranging from creative to off-the-wall item to random acts of kindness captured by video or photo. Participants can form their own teams or they will be organized in teams of 15.

Winners will be chosen from those who earned the most points, judged by completion of the item and how creatively or deeply one performed it.

Watch the video about GISHWHES below:

See Business Insider's exclusive peek at challenges described as "weird" from previous Gishwhes years: