The Daleks have been The Doctor's most vicious enemies since almost his first adventure. As such, when the Time Lords offer a chance to destroy them once and for all, he can't accept fast enough.
However, on the war-torn world of Skaro, hatred and xenophobia have completely eliminated any semblance of love and tolerance, and The Doctor and company could likely be the first ponies in history to be 'exterminated'.
A ponification of one of the most beloved Doctor Who stories of all time.