Watch full Mighty Morphin Power Rangers Season 1 Episode 10 full HD online. Cartoon video Mighty Morphin Power Rangers Episode 10 online for free in HD. Happy Birthday, Zack. The Ranger teens and Ernie plan a surprise party at the Juice Bar for Zack. The secrecy leads him to believe that they have all forgotten about his birthday. Rita shows that she cares–about seeing to it that he never again lives to celebrate any others, that is–by sending down a special treat, a vicious black armored monster known as Knasty Knight. Zack soon finds out he is way over his head. Happy Birthday indeed.