The Hero's Ally

Possibly the Hero's best friend, closest ally, and one of Hero's largest problems. Might be another member of Hero's race, a Flying Guide, Flying Non-Guide, Small Cute Animal, Small Cute Animal Plus, GREAT BALL OF LIGHT, Animated Inanimate, Robo Buddy, or what have you.

Ally As A Side
If they're too small/weak to fight alongside Hero or provide some sort of useful service (be a guide), they're more of a side than an ally. As a quick note, the difference between a side an an ally is that sides are usually there just for show and attracting a younger audience who like things such as Small Cute Animals while allies actually do something.

Hero's Ally Types

 * Typical: Someone/something that is there with Hero and lends a hand in combat when needed, but is no better than Hero, yet still strong enough to serve their superior counterpart.
 * Pathetic: Someone who gets in more trouble than usual, resulting in them derailing Hero from their adventure. This type of ally is seen to be more of a liability than an asset. This can get annoying to the point of the audience hating this character and praying they Burn In Hell.
 * Better: Sometimes, the sidekick deserves to be in the spotlight. This means that they're more powerful, more capable, or more worthy of being the main hero.