I like the idea of both mounts and spooky heroes (need to define a list on that).
With Halloween at the end of the month, it would make sense to have a collection of heroes/items that reflect that (Valve Halloween chest anyone? Someone be sure to notify them of our intentions this time
I do agree that Mounts would stretch the skills of many people (myself included)... but the field is very weighted on that subject matter, with some artists here having done many mounts before. Depending on the person, it could be very discouraging or an opportunity to grow. My 2 cents.