That may be explanation enough for most, but gameplay-mechanics-wise, this picture makes fun of the "Riding" skill, and how you can ride anything that is an ally/pet, no matter how ridiculous. The Defender is "riding" a snail, which is a fairly crazy choice, even in-game, as snails have horrible speed (unless that's a super-snail like shinesnail or something). Player Character is riding a Black Angel, which is slightly more "reasonable". However, I think the Cat Sister has the "mount" bitflag that makes her have less penalty for being ridden, so she would be the most sensible choice. By game standards, I mean; Everything Elona is crazy by normal standards.