Leo (Fallout: New Vegas)

Leo is the name of a possibly fictional character mentioned by Lily Bowen.

As it was mentioned by Doctor Henry, Lily is mad, but not dangerous. Leo, however, is all about aggressive and sociopath behavior. When the Courier asks to Lily who is Leo she says that Leo is a very nasty person that always tells her to do bad things. Lily also tells the courier that Leo was the one that instructed her on making her Vertibird sword using parts scavenged from the Vertibird wreckage on Klamath back at west California.

It is mentioned by Marcus that the Nightkin suffer from schizophrenia induced by their prolonged use of Stealth Boys and during the dialogue with Lily, the Courier may ask about the location of Leo, Lily replies by saying that he's right there by her side, the Courier may then try to convince Lily that there is no one there (to no avail of course). It's very likely that Leo is a hallucination resulted either from Lily's Stealth Boy schizophrenia or from her psychological trauma of seeing her vault invaded by Super mutants and beeing diped into the Vats.

The creation of "imaginary friends" seens to be common between the Nightkin, Davison takes his orders from a dead Brahmin skull which he calls Antler and Tabitha's radio show is nothing but Tabitha talking to herself and alternating between her own voice and her imitation of the voice of Rhonda.