And it looks like this one won't wipe your save file.
http://www.nintendoworldreport.com/news/41548/hydra-splatling-unlocking-in-splatoon-tonight
Another Splatoon update will drop this week in the form of the Hydra Splatling.
The long range weapon fires ink in a similar fashion to a fire hydrant, but it's balanced by a long charge time. It brings the Splash Bombs as a sub and the Echolocator special. The weapon will come at 11 a.m. JST tomorrow, or 9 p.m. Eastern time.
The Hydra Splatling is perhaps best known among Splatoon players for being wielded by a since-banned hacker who was playing as the still-unreleased Octoling.