Back 50 years ago, Gerald created "Project Shadow" to benefit mankind... But one of it's forms was female, which was meant to be more...loving. To take care of Maria. Sadly this didn't work too well due to Biolizard's more monsterous form. And with Gerald's execution and everything, Biolizard was locked up. After being defeated 50 years after by Sonic and Shadow, Biolizard reverted into "her" female form, trapped forever...on the ark. Lonely and waiting for someone to join her.
((Yeah don't hate, I got bored and made this... -waits for overly OCD SA2 fans to bitch me out for every reason they don't think this should happen.- And if I don't get bitched, THANK YOU! HAVE A NICE DAY! ))