Thanos is the brother of the Avenger Starfox. Both are from the moon Titan. Thanos is obsessed with Death and his life goal is to create death and be with her. Thanos has long been one of the main cosmic villains in the Marvel Comics universe. He resembles DC Comics' Darkseif a lot, but this more through years of development rather than a real copy.
The Thanos action figure was created by ToyBiz and designed by Bowen Design and released as part of the Marvel Select action figure line which features quality action figures with large diorama and props. This was probably the first Thanos action figure released, although Hasbro released one in the fall of 2010.
As all Marvel Select action figure, expect a high quality sculpt and great paint application. The articulations are minor on this action figure mostly dies the thickness of Thanos' build. He's thick. Like the Hulk. he has a few articulations at the usual places and a glove that can be replaced by a hand with the Infinity Gauntlet. He also comes with an action figure of the personification of death. This second action figure does not move much but you can put the face of a woman over her skeleton skull.
This figure looks good but that's about it. There's not much you can do to pose it although there are articulations at the biceps, elbows, knees, hips, neck, shoulders and more.
Although this action figure was released in 2005, it is easy to find. The Marvel Select collection is always in stock and comic book stores can easily reorder new stock. You should pay no more than $25 for this Thanos action figure.