Grahm does take damage from enemies but will quickly recover from an attack and will not respond to attacks from player characters. He will however fight enemies that are present along his route and this can be used to the player's benefit by leading enemies toward Grahm to fight.
Grahm can be found walking around Vault-Tec Agricultural Research Center.
At night, Grahm will eventually stop moving.
Grahm's official route is currently unverified, but an approximate map has been created.
Grahm speaks of a "smarty" but does not fully explain. Apparently "smarty" cares for Grahm but left him.
Grahm has been seen near Hillfolk Hotdogs and when near there he says that this place is familiar and the meat he smells is familiar and meat is where the home is.
Grahm has been heard talking in general about hearing music and wishing to dance but has no one to dance with.
PC Sometimes Grahm may be found without Chally the moo-moo following him, even though he continues to speak dialog talking to Chally. It's likely that Chally can become stuck on terrain. [verification overdue]