The ape is a chimpanzee. He looks nice and harmless enough so you decide to follow him as he climbs deftly the trunk then through the branches. After all, your options are limited. Tarzan should have helped you out, but that jerk just dumped you in the wild jungle. Literally! What an awful guy! You hope he gets eaten by crocodiles. And because of this jerk, you are now a young teenage girl! It's awful! As an ape, before Tarzan poured this phial upon you, you still had your penis and testicles! And you had fur so you didn’t have to worry about being naked. Now, it's more of a problem if someone shows up. You doubt this chimp and his pals will really care. Still, you cannot believe you are now stuck in a teen girl's body! Yuck! You were a grown adult male this morning! How vile and disgusting! As you stare at your crotch, you feel that you will hate your new genitalia with a passion. The idea of squatting and... Ugh! The mere thought of having teen boys interested in you and of all the "joys" of being a teen female is enough to bring you to the brink of madness. How awful! How are you going to survibve without your penis? You cannot just forget you had one!
And while you are reeling under all the implications of your new body, you glimpse the chimp travelling across branches and foliage, appearing and disappearing. You follow his footsteps dutifully, wondering where he is taking you.