In the wake of "The Mummy Returns" in 2001, Universal's animation division created an animated weekly series follow-up to the film series, airing on Kids' WB!, continuing the adventures of Rick & Evy O'Connell and their son, Alex, who now has the Manacle of Osiris bound to his wrist. I guess they needed some sort of gimmick to make the show work.
Rights issues prevented the producers from drawing Rick & Evy in the likeness of the movie's stars, Brendan Fraser & Rachel Wiesz. That, in a nutshell explains why Rick went from being dark-haired to a blond, and voiced by John Schneider (Smallville, ex-The Dukes of Hazzard). Unfortunately, the series never really got off the ground the way it was meant to, due to Kids' WB!'s practice of rotating their programs and making unannounced schedule changes at random, all the while favoring the anime that was drawing the most ratings.
The second season was delayed until February '03, and the series was given a subtitle, Secrets of the Medjai, but the 5 month delay sealed the show's fate, as it was cancelled for good in June '03. After a cable run on Toon Disney (now DisneyXD), the series has not been resurrected, even though a 3rd "Mummy" movie has since been released (and wasn't a big hit). At the very least, though, it did reach a definitive conclusion, something rare for an animated series.
Here's a trailer for the DVD release: