Seems like this mysterious creature is from a [[Kantai Collection]] wall scroll "commemorating the game reaching 800,000 users":http://i.imgur.com/LKbVuNg.png.

Seems like this creature appeared with [[shigure (kancolle)|Shigure]] "during Christmas.":/posts/1870596

Seems like this creature also appeared with [[kawakaze (kancolle)|Kawakaze]] "during a festival.":/posts/2117313

Seems like it's related to [[yuudachi (kancolle)|Yuudachi]] somehow?
夕立っぽい生物