Originally Posted by Faera Gaelwyn
Technically, Nunu is the mount, and for some reason he's carrying a little kid on his back (haven't read his lore, so idk what that's about)
Sejuani is doing the riding. Therefore, she is the first 'mounted' champion.
I imagine she'll be a slight bit on the squishy side of tanks, seeing as she has no defensive benefits to her skills. Since her damage skills sound like they'll be AP based, Rylai's will probably be a must on her.
To all those who are complaining about her lack of clothing:
She is from a very cold region, and will be fighting on very warm maps (winter SR won't be here forever).
Generally when you are accustomed to cold climates you wear significantly less when staying in warm places. I know that doesn't explain why she wears so little on that icy splash art of hers, but her lore gives that explanation.
If you've read Nunu's lore Nunu is the kid at the back of the sasquatch.. Rumble is also the yordle who mounts the robot not the robot itself. and corki is mounting the copter.. which means she is the "4th" mounted champion.. unless in your point of view that riding a sasquatch, a plane or a robot is not a classification of being "mounted"