Another example: Awakened Dire Ape as an animal companion to a Drd18:
15d8+30 (101hp)
AC 29 (–1 size, +4 Dex, +4 chain shirt, +12 natural)
10' Reach
BAB +11/+6/+1
SA: Rend 2d6+12
SQ: Darkvision 60', low-light vision, scent, link, share spells, evasion, devotion, multiattack
Full Attack: 2 claws +16 melee (1d6+8) and bite +14 melee (1d8+4)
Abilities: Str 26, Dex 19, Con 14, Int 10, Wis 12, Cha 9
That's an entirely non-magical AC 29, and the same hp and a better attack sequence than a 17th level Ftr. Entirely empty-handed mind you! And because it's an ape he can use all the same equipment the Ftr can: Large greatsword 3d6+12, 20' reach 2d6+12 large spiked chain, potions, rings, whatever...
True, the Ftr will have 9 more feats. But the Ape gets other cool benefits, such as Darkvision, Evasion, Rend, Share Spells, Multiattack, etc...