| # | Book Title | Author | ||
|---|---|---|---|---|
| 1 | Earthlets, As Explained by Professor Xargle | Willis, Jeanne | ||
| 2 | Earth Hounds, As Explained by Professor Xargle | Willis, Jeanne | ||
| 3 | Earth Tigerlets, As Explained by Professor Xargle | Willis, Jeanne | ||
| 4 | Earth Mobiles, As Explained by Professor Xargle | Willis, Jeanne | ||
| 5 | Earth Weather, As Explained by Professor Xargle | Willis, Jeanne | ||
| 6 | Relativity, As Explained by Professor Xargle | Willis, Jeanne |