Fallout 4's post-apocalyptic setting has allowed the games' various developers to create some very weird and wonderful creatures over the years, many of whom you wouldn't want to meet in the dark.
Aside from the always pleasant company of Dogmeat, you'll likely come across horrors like the Deathclaw, Yao Guai or the genuinely quite gross Centaur, none of which you'd want to keep as a pet.
Some of the most terrifying creatures in the Fallout lore didn't even make it into the final game, though I'm personally glad I never had to fight the May Pole.
That said, being alive after the end of the world likely shifts the contextual goalposts quite a lot, and who knows how appealing it would be to tame one of those if you're already living in the worst timeline.
Advert
Well, it seems that there are certainly some people out there who want to get the wastes deadliest beasts under control, and there's one in particular that they have in their sights.
Fallout Player Wants The Red Death as a Pet and We Don't Know What to Say
Over on Reddit, one Fallout 4 player shared an image of The Red Death, one of the deadliest creatures in the Commonwealth, asking the gathered forum if there was any way for them to "keep it".
If you aren't familiar with The Red Death (and count yourself lucky if you aren't), the creature is a unique and massive bloodrage mirelurk, the likes of which you've never seen, that you can take on in Fallout 4's Far Harbor DLC. The monster has built up a reputation for itself as a destroyer of ships.
Now, it may be that the legends have exaggerated the creatures stature somewhat, but you'll need to go and track it down for yourself to find that out.
With that context, I still have no idea why you would want to keep one as a pet, something which the comments mostly agree with me on.
"A Red Death is a really big commitment, maybe start with a radrat first to see if you're ready," one particularly funny comment read.
"You wanna keep the demon known as the Red Death? THE RED DEATH. Are you out of your mind?," another wrote.
"That's like trying to keep a Deathclaw with rabies and custom fitted power armor on it. You are going to die and whatever settlers around you are going to die".
Unfortunately, it's not possible to tame and keep The Red Death, so OP is just going to have to go with something a little more conventional for company.