24 Pull Requests
If the Pull Request Challenge hasn't provided enough pull request action for you, you could sign up for 24 Pull Requests. The idea is to do 24 pull requests in the 24 days before Christmas Day. You have to find the repositories yourself.
All you need to sign up is a github username.
I did this last year, and it's what prompted me to start the CPAN Pull Request Challenge. I did complete it, but only just — it got quite hard towards the end when it was clashing with Christmas holidays.