Lego and Cartoon Network collaborated to make a line of LEGO toys for Ben 10: Alien Force. They came out in 2009. A total of six of them were released: Swampfire, Humungousaur, Spidermonkey, Chromastone, Jetray, and Big Chill.
They only lasted one wave before they were discontinued.
The pieces of the figures connect when compatible connectors are snapped into their appropriate sockets. In this way, a complete model can be created, along with a vast number of other combinations. The pieces are compatible with other LEGO products, especially those which also use the ball-and-socket system. The figures also glow in the dark.