Morningstar wrote:
Strange potion. But it is much cheaper to just go to the lab ray page and keep refreshing until you get the Mad Scientist as a challenger. Then fight him in the BD. More often than not, he will use the strange potion that he has in his cache of weapons. That will immediately change the gender of your pet. As soon as he does that, withdraw from the fight.
True but be warned that it can (in some cases) literally take forever to get him as a challenger
I still haven't had the RE after trying for more than a year
Having said that MD, you may be lucky and get him almost immediately so good luck with it!