You may have that known of the existence of a Scorpion King film that was a spin-off of the Mummy franchise,starring Dwayne "The Rock" Johnson in the title role. It made sense to give the final boss of The Mummy Returns his own film given the Rock's immense popularity and the commercial success of the film (and for a chance to give some much-needed context for that dreadful CGI half-man, half-scorpion).
Source: blastr.com