Zionanthani said: Are they driving miniature castle towers?
Of course. This is Yamaada, he would never draw any sort of transportation that wouldn't make any sane person go "what the hell?". That's part of his charm.
Laethiel said: Drivable mini-towers are actually a lot saner than most forms of transportation from Pixiv Fantasia.
On the other hand, most of the truly bizarre Pixiv Fantasia transportations were invented by Yamaada. See the chicken-powered land fortress or the unicycle-horse for examples.