Two ideas that I've tried before, both of which indulge my interest in exotic creatures, but not necessarily serpents.
1. The Journey Home
Two anthro characters (male and female, specifics up to each player's choice) escape from a human "zoo" after being abducted from their distant homeland. Initially, the players do not know each other so a large part of the RP early on is the discovery of each character- their history, abilities, likes and dislikes. The two then try to return home. In their path is an accursed forest, populated by a variety of seductive and deadly creatures. The story chronicles their adventures in returning to their homeland. The specifics as to the creatures/ perils encountered are up to the players' individual preferences. When I've run this in the past, I play the male character and any creatures which are my creation. Ideally, my partner would play the female and any characters which she contributes.
2. The Farm
A woman looking for help after getting a flat tire stumbles into a strange, "living" trap. When she wakes up, she finds she's been taken captive by a mysterious character named "Brumgard"- the curator of what appears to be a farm for exotic creatures. After a brief (and somewhat forced) erotic encounter, she discovers that he is not entirely human. In return for her compliance, she is given her freedom- she only needs to find the means of escape from the place. As she attempts to escape, she comes to realize the place is more than it seems, and has a much more sinister purpose. Does she survive? Does she merely escape or attempt to expose Brumgard's "Farm" for what it truly is? When I've played this in the past, the lead female character is played by my partner. I, in turn, play Brumgard, and the variety of denizens the woman meets in her efforts to escape- some friendly, some not. There is also the opportunity here to recruit "guest" players to play some of the creatures, though I've found this easier said than done from past experience.
The stories are freeform, and the path of these stories not set in advance- it is determined by characters' actions. I also encourage the player to bring some of her own favorite creatures, which can easily be worked into the story.
