Human

The term human is used in the TV show, despite all of the characters appearing as anthropomorphic animals. Instances include:

Albums

 * Poetry Club (track): Buster: "Finding a human bone in your jello"

Books

 * Mrs. Tibble in Arthur's Halloween and she and the Tibble twins in both Arthur Babysits and D.W.'s Guide to Preschool, although all 3 become bears in the cartoon

Season 1

 * Arthur and the Real Mr. Ratburn: Buster: "Get with it, Arthur. We're not dealing with a human being here. This is serious!"

Season 5

 * The Last of Mary Moo Cow: "only one person stands between crime and humanity"
 * You Are Arthur: in the introduction "Human treasure, lad, not buried treasure"

Season 6

 * Arthur Loses His Marbles: Buster: "Oh, the humanity!,"

Season 13

 * Paradise Lost: when Kate begins to lose her comprehension of Pal's speech, Amigo explains "This happens to all human children. I remember when it happened to Vicita."

Season 17

 * Dog's Best Friend: Pal asks, "Who knows why humans do anything?"

Season 19

 * Brain's Brain: Arthur says, "I wonder how many neurons there are in a human brain."