This was a Ben 10 flea market hunting as we also found two really big Ben 10 figures of both Humungousaur and XLR8.
Humungousaur stands 6-inches tall, with multiple points of articulation, and features a trigger on his back that activates fighting-mode action! His arms lift up as his mouth opens and chest muscles flex. Its a great looking figure!
As for XLR8, the button on his back activates the water and propeller contained behind his transparent chest plate and features cool oozing DNA Slime bubbles. There are also wheels on his feet and tail. I have seen this action figure going for around $80 on Ebay and Amazon... we got it for $2.