I gave two meat-eating unicorns away when I quit and there's precious little in-game that I've regretted more. I had betaed Third Dawn (yes, you can blame me for it!), so the uni's meant a lot to me.
Only many, many years later, was I able to replace mine when a leaving player gave me his meat-eating unicorn.
With increased stable slots on the radar, I'd hang on to her. Just me, though.