How to catch the Mimic Fish?

Form pocketgamer.co.uk:

Mimic Fish - $35 - M
Hint: "Location Unknown."

Solution: Somewhere deep in the Maelstrom. Developer Vlambeer says it's "really rare", and that it appears around midnight (though wouldn't confirm that it appears exclusively at midnight).

We finally caught it by setting the time on our device to midnight; putting on the frozen hat and emperor's suit; and diving deep into the Maelstrom.

Found it at ~1500m, during the day (not midnight), using the emperor suit (can’t remember the hat). It was next to several vertically aligned Goose Boosts, so you should avoid those in order to be able to catch the Mimic Fish.

Apparently, when it’s in the air, it looks like some jelly fish, to avoid being shot.. so you should shoot some jellys to be shure. Can’t tell for shure because I shot several at once and couldn’t see it.