From Muppet Wiki

Kermit's 501 Fun Facts is a 1995 children's book of interesting and wacky trivia, presented in 501 bite-size chunks. The wide-ranging topics include how yeast works, how far a kangaroo can jump, why the Moon's gravity is lighter than Earth, and the inventor of the donut.

The book is illustrated with cartoons as well as a variety of Muppet photos. Most of the two-page spreads have at least one Muppet photo, and some have as many as four. Many of the photos are from Muppet Magazine; there are also some from the Miss Piggy calendars, Miss Piggy's Guide to Life, The Muppet Show and The Great Muppet Caper. There is also one picture of Flora the Koala from The Animal Show and a picture of Frankie Frank and the Footers from CityKids.

There's only one fact in the book about the Muppets -- fact #501 is about Jim Henson making the original Kermit the Frog from his mother's old coat.