A person who flirts with as many people as possible, and then rejects those who inevitably fall in love. Stems from an unhealthy low self-esteem, as they want to feel loved by as many people as possible, regardless of whether or not they actually like said people. Originated from the idea that people don't know whether a mongoose eats a snake or a snake eats a mongoose.
1 - I think I've fallen in love with you...
2 - Oh... well, sorry, I don't feel the same.
1 - What? But you've given me all the signals!
2 - Oh yeah, haha, I tend to do that. ^^
1 - You're such a mongoose. :'(
2 - Excuse me?