Elephant puppies
African Elephant
Arthur, Perky the Elephant, and Mrs. Wood with the elephant puppies
Animal Elephant
Family Perky (mother; imagination only)
Book debut Arthur Writes a Story
Cartoon debut "Arthur Writes a Story"
The elephant "puppies" appear in two versions of Arthur's story in "Arthur Writes a Story".

Story 1

After Arthur told Mrs. Wood that Perky had "elephant puppies", Perky as an elephant and her "puppies" broke through the second story floor and fell in front of Mrs. Wood and Arthur.

Story 2

On the Moon, Arthur told Mrs. Wood that Perky had puppies. Perky and the puppies were floating because of the lower gravity of the moon, but as Brain explained, they would be lighter, but would not float up to the ceiling.