In the entire series of ben10 the it is Alien X, but just the ben10 Original series then it might be the 200 feet tall Waybig.
3 1st ben10 2nd ben10 alien force 3rd ben10 ultimate alien
no but he will return in the third series ben10 ultimate alien
alien x is oiaa
ben10 isn't im not quite sure if there is more than one version, like if it is the alien force but i know ben10 isn't over
no
its oiaa
Cybo-Chip.
nanemech
THE best alien of ben-10 ultimate alien is alien x.
NO
== == its rame
the hive