A "has hands" style beast companion might be useful for some. The only problem being, that Baboon is the only one that fits in under the 1/4CR or less rules. So no rock throwing Apes of doom for you
The 4x Ranger level HP thing isn't bad for it, it has a climb speed and uses Pack Tactics.
The main use for it is: It is essentially a small humanoid with hands! This is an amazing thing.
Any magic item that doesn't need attunement will essentially fit this guy. Any common items (caltrops, ballbearings, lanterns, oil, torches, alchemist's fire, holy water, etc) can be carried and used by him.
He might not be a combat pet, but he is awesome in every other way. He even has 4 Int. 4! That's like as smart as a barbarian! So he can do pretty complicated things for a slave. Umm, beast companion. Yes, that is what I meant....
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Just for another dumb thing. Stealth Ponies.
If you have, say, plains as you favoured terrain, can hang out by a horse corral for 8 hours while hidden, then you can steal a pony and ride out of there unnoticed at full speed. Rangers are the greatest horse thieves in the land. It's how they support themselves considering their otherwise shitty class abilities.
Works with mules, riding horses, ponies, mastiffs and elks (cattle?).
Stealth Ponies are great.