Fluttershy was taking an innocent walk through the Everfree Forest, totally not in search of any lewd mysterious black vines she'd heard so much about.
Unsurprisingly, Fluttershy happens to find a tentacle monster... just not the kind she was expecting.

His name is Frank, he likes cats, and much to Fluttershy's disappointment, has absolutely no libido whatsoever.
(Rated for innuendo.)