During his stay, Ben discovers the Omnitrix, an alien device that allows him to change his DNA to that of various aliens' and take on their form. While on summer vacation, Ben Tennyson stays with his grandfather, Max, and cousin, Gwen. He uses this device very carefully and very responsible. Two of my favorite alien forms are Ben 10 Diamondhead and Ben 10 four arms.
The story of Ben Tennyson, a typical kid who becomes very atypical after he discovers the Omnitrix, a mysterious alien device with the power to transform the wearer into ten different alien species. Who is Ben 10 you may ask? Let me tell you something about this adventurous kid that is always on a run for fighting with monsters.