Max Tennyson (Classic)/Ultimate Alien

In Hit 'Em Where They Live, it was revealed that Max had been protecting the Tennyson family from being attacked by Ben's old enemies (due to Ben's secret being revealed to the world). However, he was injured while protecting Sandra from SevenSeven and was forced to inform Ben and his team of the problem.
Max appeared again in Ultimate Aggregor, where he helped Ben, Gwen, and Kevin stop Aggregor. 
In Map of Infinity, Ultimate Aggregor's electrical shock damaged his entire nervous system and had to be replaced. Azmuth brought him, along with Ben and his team to Galvan Mark II, where Max was placed in a tube that would repair his nervous system after a few weeks.
Max returned in Absolute Power: Part 1 and Part 2 with his nervous system having been fully restored and helped Ben and Gwen stop Ultimate Kevin.
Max appeared in Prisoner Number 775 is Missing, where he was furious when he learned of alien prisoners being held in Area 51 illegally and as a result had gotten into a major disagreement with Colonel Rozum.