It's from the dead game, Chronopia. Prince August now owns the figures. You can occasionally still find them in stores with old stock. I got two of them out of a discount bin years ago.
http://shop.princeaugust.ie/chronopia-eternal-realms-games/sons-of-kronos-faction/tg2820-chronopia-sons-of-kronos-monarch-figures/
Two things, Prince August has regular sales during the year on their Warzone and Chronopia stuff. You can get a better deal if you wait. Sign up for their newsletter and you get notifications when they have their sales. I think they usually have one around Christmas time.
Another bigger problem though is the high amount of their Warzone and Chronopia stock that has lead rot. Blistered items like the Sons of Kronos Monarch fig, which this stead comes with, tend to have less lead rot in them. Most of the boxed set Chronopia items I've gotten have had from light to heavy lead rot. Especially those that didn't have their lead parts packaged in plastic bags in the boxes. Those that had their lead parts against the "protective" foam in the boxes have lead rot. Some of it was really bad. I got a Firstborn Chariot shipped to me by mistake, in an order. I offered to return it but they said keep it. I was excited, until I opened it. Once I opened it I realized it wasn't a gift after all. The lead rot was so bad almost all the detail was gone. It looked more like an armature for a chariot than a chariot. All of it's parts were not in plastic bags and pressed against the foam.
I noticed that when they redid their web store for the Warzone and Chronopia items that a lot of their items are no longer available. Maybe they went through their stock and go rid of the stuff with lead rot.
The new Chaos Marine gun dinosaur looking things look a lot like the Hungry Hungry Hippos in general shape!