Henry's family takes in a stray cat, the ugliest cat they have ever seen, and an amazing relationship blossoms between it and their big dog Mudge.

Henry worries about what will happen to his big dog Mudge during their visit to his grandmother's house in the country.

Henry and his big dog Mudge attend a family reunion.

In the autumn Henry and his big dog Mudge watch the leaves turn, meet with some Halloween spooks and share Thanksgiving dinner.

Henry and his puppy, Mudge, search to find Mudge's missing favorite blanket.

At Christmastime Henry and his dog Mudge enjoy baked treats, visits from relatives, lots of presents, and each other.

While trying out the spy glasses, spy hat, and other items in their new spy kit, seven-year-old Henry and his dog Mudge make a new friend and form a spy club.

No one loves to play more than Henry's puppy, Mudge. And when Fluffy the cat joins Mudge for a play date, the games are just beginning. From running to hiding to climbing galore, these two just might prove that cats and dogs really can be friends.

At first Henry's very neat cousin doesn't like the cookies from under his bed or Mudge's slobbery kisses, but when they all play frisbee, she begins to enjoy her visit.