Like Brionne, Braixen, Dartrix, Fletchender etc.
As Geeky Jawa said, there was an Other Metagame of the month called Middle Cup which sets all Pokemon to Level 50 and limits you to using Pokemon with a pre-evolution and a third evolution. This is not a set ladder, therefore it cannot be used unless it gets voted on again as OM. You can read about it here.
To stay updated with showdown's tiers you can visit the Competitive Discussion forum on Smogon.