Pal

Pal is Arthur's pet dog.

History
In "Arthur's Pet Business", Arthur watched many animals including Mrs. Wood's dog, Perky. Mrs. Wood had a list that he needed to abide by for Perky to be happy, such as brushing her 100 times. When Mrs. Wood was about to pick up Perky Arthur believed that he had lost her, but she was actually giving birth to be a litter of puppies behind one of The Reads' chairs. Mrs. Wood let Arthur pick Pal out of the litter because he was a good petsitter.

Physical appearance
Pal is a small golden-haired dog with smooth fur. When he was first born, he had fuzzy fur. He wears a red collar with a silver pendant attached to it. In the TV series and CGI movie, his eyes are black; although in the books and in many detailed illustrations, they're normally white with a black dot in each one, but he is occasionally seen with black eyes.

Personality
"People are the most illogical, strange and frustrating creatures on the planet. Still, they do know how to make a top-notch ham-bone."

- Pal

In some episodes, it's shown that Pal can communicate with other animals and human babies. In these episodes, he speaks with a high-brow British accent and acts sophisticated. He likes to sleep under the couch, but he usually loves to sleep on Arthur's bed with him and comforts him by licking him after he has a nightmare. He dislikes being alone in places.

When he was a couple of weeks old, he was easily excited and not housetrained. He bit his leash and popped the tire of Francine's bike with his teeth. Because of doing these things Arthur's parents gave him the options that Pal will either stay in the garage or be sent away until he was housetrained, both of which were to Arthur's objections. However, Arthur spent a lot of time training him and he has since then learned to become a fairly-intelligent dog. He only knows basic tricks, such as sit, and Arthur failed to teach him more complex orders.

Relationships
Pal generally gets along well with others and always wags his tail, with the exception of pet cats, in which he has ailurophobia (fear of cats).

Friends

 * Arthur Read: He is Pal's main owner in the family whom he is always tended by. At night, he enjoys sleeping on Arthur's bed with him. Arthur always say positive things about his dog, and refers to him as the "smartest dog on Earth", even though Pal occasionally makes mistakes, such as turning off the computer when Arthur is doing his homework.
 * D.W. Read: She always refers to him as "Arthur's crazy dog"; and even though he likes her, she always thinks he's bothering her, but she sometimes treats him nicely.
 * Kate Read: In "The Secret Life of Dogs and Babies" from Season 6 and many subsequent episodes, they are seen talking to each other and with other pets and babies, but the people older than Kate's age dismiss it as gibberish whenever they're around. His first known friendship with her was when he ran across Elwood City to get a balloon to cheer her up in "Arthur's Lost Dog".
 * Amigo: He is the Molinas' dog whom Pal became best friends with after the family moved into the neighborhood in Season 6. He often has adventures with him and Kate.
 * Brain: When he came over to stay at Arthur's house when his parents went to the Ice Creamer's Convention, he taught Pal some tricks, such as walking on his hind legs than on all fours. His friends once imagined him getting a puppy who looks like Pal, but with brown fur instead of golden.
 * Buster Baxter: When he comes over to Arthur's house, he seems to have fun with him too, such as petting and massaging him.
 * Francine Frensky: When she comes over to Arthur's house, he seems to get along with her sometimes, such as when he licked her face at Arthur's 8th birthday party. However, he dislikes her cat, Nemo, far more than her as of Season 4. She also once mentioned that she was sad that she didn't even get a puppy.
 * Killer: She is a stray lap dog that was found on Grandma Thora's front porch from the episode, "It Came From Beyond" which marked her first appearance. She bit Pal on the leg. However, Thora convinced her to be more friendly and she and Pal are now friends.

Neutral

 * Muffy Crosswire: She and Pal don't have much of a relationship with each other. When Pal was lost in Elwood City just to get a balloon to cheer up Kate, she referred to him as a "rude little dog" every time he ran off whenever she and Francine wished for him to thank them.