The male tourist seen in the beginning of this episode was the same one seen in China in the episode "Year of the Rat".
Max: Come on, Virg. The only dinosaur living in Hawaii is big and purple and sings on TV.
Virgil's means of summoning: Pondering the countless traveling possibilities with the use of the Cap, Max skims through a travel magazine. He sees a picture of Norman and Virgil in Hawaii holding up a message while surfing. The message was "Visit the zoo".
Educational Epilogue: Alligators and Crocodiles. Descendants of the dinosaurs.
Dr. Zygote was the villain Max faced in the Dino Lab playset in the Doom Zones line of the Mighty Max toys.
Max: The only dinosaur living in Hawaii is big and purple and sings on TV.
Max is most likely referring to Barney the singing dinosaur.