Leo (Fallout: New Vegas)

Leo is the name of a possibly fictional character mentioned by Lily Bowen. It is, at this time, impossible to say whether or not Leo is imaginary, a product of Lily's Stealth Boy-induced schizophrenia, or if he is someone she actually knew once, possibly from before she was dipped.

There is a super-mutant character called Uncle Leo in the DC Wasteland in Fallout 3. It's unclear if this is just coincidence, or a deliberate reference by the game developers.