This mini requires assembly (duh). The body and the two middle heads are one piece, the end of the tail is another piece, the other three heads are separate pieces, and the rock/base is a separate piece. Phew! To top it all off, the necks all have little spikes running down the back, so holding it while you glue or paint it means you're stabbing your fingers. However, the result is damn good.
I normally don't like minis that have a lot of built-in scenery on the base (treasure chests, skulls, etc.) as that stuff may not always be appropriate to where I place the monster in an encounter. However, in the case of this hydra the rock is a godsend, not because of any terrain needs but (and I suspect this was deliberate) to elevate the front of the body from the battlefield, which moves the heads out of the way of creatures on the ground. In other words, I can bring other minis up against this one without running into the heads.
The necks are already cast in a bent position, but they're thin enough that you can bend them slightly to tweak their exact positions (I have two of these guys, so it's important to make them look a little bit different).
Base color is black, drybrushed with Aged Red Brick. The necks are also drybrushed with Maroon, shading toward a strong drybrush of Blood Red on the heads to make the heads stand out from the big body. It's hard to tell in this picture, but four of the heads have yellow eyes and one has light blue eyes (in the original myths, one of the hydra's heads was immortal and couldn't be killed, so if I wanted to suggest that in a game with a hydra, I could point out one of the heads as a little different than the others.
Base is a 1.5" washer glued to a 1.5" plastic GW base. I glued the mini to that and smoothed the transition with putty.