Rex Companion Quest and Location Guide: Best Ending and Brain for Rex

Rex is a recruitable companion in Fallout New Vegas (FNV). Read on to know more about Rex's companion quest and location, best ending, best brain, how to recruit, companion perk, and more in this guide!

Attention!	This section contains spoilers! Please proceed with caution.

Rex Companion Information

Rex Overview
Faction	Non-aligned
Perk	Search and Mark
Race	Cyberdog

Rex is a cybernetic dog living in Freeside with the Kings. He can keep enemies busy with his quick melee capabilities that also come with a knockdown effect. This makes him a great companion to bring along for those who wish to keep their distance during fights.

Rex Location Guide

King's School of Impersonation

You can find Rex inside of the King's School of Impersonation in Freeside. Head towards the door on the left upon entering the building and talk your way through Pacer to access the stage. The King can be found sitting directly in front of the stage right next to Rex.

All Maps and Locations

How to Recruit Rex and Companion Quest

Investigate Orris for The King

	Objective
1	Talk to The King He will tell you to investigate a bodyguard named Orris at the Freeside north gate. Have Orris escort you to The Strip's north gate to proceed with the next objective.
2	Report back to The King Report your findings about Orris' operation to The King and you will get the dialogue to ask about his dog Rex afterwards. This unlocks the Nothin’ But a Hound Dog companion quest.

Nothin’ But a Hound Dog

	Objective
1	Talk to Julie Farkas at the Fort Go to the Old Mormon Fort and ask Julie Farkas about Rex's condition. She will tell you about Doctor Henry, an old scientist in Jacobstown who can perform brain surgery on Rex.
2	Bring Rex to Jacobstown Inform The King about the possiblity of curing Rex and he will ask you to bring the dog to Jacobstown to find out more.
3	Talk to Doctor Henry Talk to Doctor Henry inside of the Jacobstown lodge. He will give you three choices for which brains can be transplanted into Rex.
4	Choose a Brain for Rex Choose a brain for Rex and set out to its location. Bring the brain back to Doctor Henry in Jacobstown to begin the operation. You can keep Rex as a companion after choosing a replacement brain for him at the end of the quest.

Which Brain to Choose? ▼

Rex Companion Perk

Search and Mark Perk

While travelling with Rex, you will gain the ability to highlight chems, firearms, and any ammunition you come across while aiming down your sights or zooming in, making the items easier to spot. If any of these items are within a container, the whole container gets highlighted instead.

Best Ending and Brain for Rex

Use Rey's Brain for the Operation

Get the best ending for Rex by choosing Rey's Brain as a replacement. You can get Rey's brain by talking to Old Lady Gibson at the Gibson scrap yard during the Nothin’ But a Hound Dog companion quest.

Doing so will help improve Rex's condition, his mind will settle peacefully and The King will thank you for your efforts if you ever decide to talk to him again after the operation.

How to Get All Endings

Choose Lupa's Brain for Better Survivability

Benefits from each brain only apply to Rex and not to your character.

Should you choose a different brain, we recommend Lupa's brain as this increases Rex's toughness, effectively allowing him to be more durable in battle. This allows you to focus on taking down enemies without having to worry much about Rex's wellbeing.

Do note that you can choose any of the other brains should it benefit your playstyle or build.

Fallout New Vegas Related Guides

Best Companions and List of Companions

All Companions

All Companions
Arcade	Boone	Cass	ED-E
Lily	Raul	Rex	Veronica