Player Model?

One of my friends I used to know was able to set his player model (on a server) that wasn’t in the list, the model was
models/Humans/corpse1.mdl
the server didn’t have a special addon or anything, would anyone know how to do it?
I found a console command to change you’re model
cl_playermodel , but I can’t get it to work :\

edit: found out how to do it. just use “corpse” and it works.

But I found this neat little model
models/Humans/Group01/Male_Cheaple.mdl
Would it be possible to set you’re player model without an addon?

Nope.

Didn’t think so, but that doesn’t explain why I can use “corpse” as a valid player model but it not be in the list.