護衛要塞
An [[abyssal ship]] from [[Kantai Collection]].  They appear exclusively in events with "Princess"-type bosses.

As a floating orb with a toothy mouth through its center and hazy breath, its appearance is identical to the [[floating fortress (kancolle)|floating fortress]].

They are also not to be confused with the more common [[Enemy Aircraft (kancolle)|]].
escort fortress (kancolle)