Zack takes home from the local animal shelter a scruffy tomcat who not only talks but claims to be the reincarnation of Zack's Great-Grandpa Julius.

Zack feels that a supernatural force is at work in his apartment when he encounters floating television sets, pancakes that flip by themselves, and a ghost named Wanda.

While Zack is being treated by Dr. Jekyll, his new orthodontist, the doctor undergoes a strange transformation into a growling monster.

Zack starts turning into a cat when the spirit of an ancient Egyptian cat goddess is accidentally transferred into his body during a class field trip.

Zack and his father go to Hawaii where Zack has an unfortunate encounter with an angry volcano goddess.

When Zack goes to Florida to visit Mel & Shirley's Wonderful World of Dolphins, he is surprised to discover that he can understand and speak to dolphins, which enables him to solve a kidnapping. When Zack is given the chance to swim with dolphins on a trip to Florida, he dives right in. But before long, Zack is surprised to find that the dolphins are trying to tell him something ? and even more surprised that he can understand and talk to them! There's...

Zack visits a very strange Chinese restaurant called Wun Dum Guy and finds that the fortunes in his fortune cookies start coming true.

In Central Park, Zack and his dad encounter an alien who has lost his spaceship, which has been towed because it was illegally parked.

A strange trip through a metal detector causes Zack's eighty-eight year old Grandma Leah to get younger and younger.

After hearing stories that a Bigfoot-like monster is haunting Camp Weno-wanna-getta-wedgee, ten-year-old Zack begins to find evidence that the legend may be true.

Ten-year-old Zack gets gets a chance to meet the old horror flim star Count Bugosi, who may or may not be a real vampire.

Zack buys a dinosaur egg and ignores a warning not to put it in a microwave oven.

After she eats his homework, ten-year-old Zack suspects that his substitute teacher Mrs. Wolfowitz is a werewolf and uncovers her bizarre secret.

Zack, his father, and Spencer fight to save the world from a rude, bossy, and hungry package of freeze-dried spores purchased at The Orville and Fanny Shlectwasser Museum of Air and Space.