Similarly, Forbiden Fruit The Tempation Of Edward Cullen, on top of the human/vampire pairings, features Jasper Cullen and a human guy he picked up in a bar having a threesome with a talking panda. Yes, you read that right.
For Your Eyes Only turns all the Naruto characters into Petting Zoo People. Naruto becomes part-cat-part-fox, Sasuke becomes part-cat-part-wolf, and they breed together. Sakura becomes a rabbit who attempts to flirt with Sasuke (and gets murdered for it). Hinata is a mouse who likes Naruto but ends up with Neji, a cat. Brief mention is made of a deer/raccoon pairing. Gaara and Lee are, respectively, a raccoon and a frog, who have babies together.
Not to mention all the fan-fiction where Naruto and the Kyuubi, or Nine Tailed Fox, hook up, which has the fox in question become part human with fox like traits. What makes it somewhat funny is that before any of the romance ever takes place the fox is already inside Naruto (yes you can spin it that way if you want) thanks to the seal, kind of makes it hard for Naruto to get away.
The World of Warcraft fanfic The Sirens of Azeroth suggests that the many species of Azeroth don't have a huge amount of trouble with, at least, casual interspecies romance/intercourse, demonstrating among others a Dwarf/Draenei (seven-foot faun-like blue alien) relationship, a Troll/Blood elf lesbian couple with an open relationship, and a pair of tiny gnomes talking about how their favorite types of 'men' are Tauren (hugeminotaurs), though they could just be making that up. Whether this mirrors the canon universe in any way is a question for Blizzard to answer.
Quite common in Redwall fanfic; for example, Leif Melyamos of Soulless Shell is a rat/mouse hybrid.
There's a currently unfinished Spliced fanfic series which pairs up the characters of Patricia (a platypus) and Peri (not known for sure, mostly assumed to be a cuttlefish/squirrel hybrid). ......Yeah, just take a minute and try to let it all sink in.
In a pornographicBen 10 fan comic, the adult Ben has an affair with Myaxx (and this was made before Myaxx got a makeover in Ben 10 Alien Force). As a result, she gets pregnant (with a son who looks entirely human), the explanation being that "the DNA flux of the Omnitrix allows Ben to interbreed".
There's absurd amounts of fanfiction that pairs together Alice and the Chesire Cat from American McGee's Alice, and now also Alice: Madness Returns on the basis that he's the only character always supporting her. It's still intensly creepy.
Very one-sided in With Strings Attached. Shag, a “lizardy, birdy” alien, is clearly in love with the (usually human) four, but it's strictly from a distance, and they certainly do not love her.
In the My Little Pony Friendship Is Magic fanfic Summer Days And Evening Flames, Gilda (a griffin) eventually starts dating her guard captain Iron Bulwark (a pony). She's justifiably worried that dating him could make others look down on him, considering his best friend is very racist to griffins.
