brain_body.mdl in Early 2007 build

[Devteam5]

The other day I was searching through Valve Archive, and I came across a zip named  Early2007_CompiledGameFiles.7z. It wasn't really anything special, just many of the final game's files, but then I found this odd model called "brain_body.mdl". It looks a bit like an early GLaDOS core.
The thing is it isn't in the Repo at all, so I'm not sure what it's for.
It's just this

[TheRealManwich912]

[DELETED]

[VALVe_installer]

In those days, a lot of games from Gabe’s office were being developed, so besides Portal it could be anything at all, up to the third episode.