Found in the Tartarus Montes region, from "head" to "foot" Slim Man is 2.22 miles in length. In width, he's around 2,000 feet at the widest.
He's so big that it is hard to imagine anyone building him unless they were extremely advanced and/or had a lot of help!
Besides looking like a slim humanoid, you can also perceive it as a fish if you squint your eyes a little.
http://viewer.mars.asu.edu/planetview/inst/hrsc/H1152_0000_ND3#start
Coordinates: 13°11'27.54"N 161°17'16.43"E
