Max Flexer's name in the original Japanese version of the show is Macho-San.
Max Flexer looks like a traditional fitness instructor. He is, of course, in great shape, since he is a fitness trainer. His hair is curly and pink, he has red wristbands, white shoes, and he wears a retro-style yellow jumpsuit that has a red sripe. He also wears a headset, and has tanned and brownish skin. He has the sunglasses of a stereotypical trainer that nearly always shine. His mouth is even larger than Kirby's, and it is full of pearly white teeth.
- Max Flexer is one of the few Demon Beasts in the show that are seen to be capable of speech.
- He is obiviously a parody of the real life fitness expert Richard Simmons, given his voice, mannerisms, and profession.
- In the Kirby Master mode of Kirby Mass Attack, he makes a surprise appearance.
- In the original Japanese version of the show, when Kirby and Dedede are exercising, Dedede's iconic theme can be heard.
- He is one of the few Demon Beasts that actually do exactly what Dedede ordered them for, the others being Delivery Man, Cold Virus, Hardy, and Paint Roller.
- He is able to get everyone but Meta Knight to dance.
- Max Flexer was voiced by Corey Burton, but he was uncredited for the role.