Unshakeable Tracker is a companion perk in Fallout: New Vegas.
Requirements[]
Gaining this perk requires talking to Doctor Henry during Nothin' But a Hound Dog about replacing Rex's old brain with a new one and following the option of finding a Fiend guard dog with a suitable brain. This can be accomplished by going to the trailer-truck base near the Poseidon gas station southwest of the South Vegas ruins.
The Fiend leader Violet commands a large horde of Fiend guard dogs, the one in question being Violetta. Upon killing her, Violetta's brain can be taken.
Effects[]
When Rex is an active companion, he gains a 50% increase to movement speed.
Notes[]
The movement speed effect is applied via scripting attached to Doctor Henry's dialogue instead of a perk.
