In the legend of zelda series, or at least the majority of it, there always has been an animal helper that aided you in some way or form. From expository banter, to travel, to even aiding you in combat, this is a staple that really makes things interesting.
Since this is a poll thread about it, I comprised most of them, but not all of them.(I haven't played all the zelda games so there are some I can't mention because I either don't remember, or don't know about it.)
Anyway, for those don't know of these helpers, I'll leave an image and basic description of what they did.
Animal helpers from the Oracle of Seasons and ages.(Within Spoiler)
Ricky From the Oracle of Seasons/Ages:
He acted as a mount that can not only punch out enemies. He also can do a ranged attack, jump over large pits and jump up some cliffs.
Moosh from the same game:
Like Ricky, he acted as a mount and was capable of combat with his ground pound attack. Unlike Ricky, he can hover for as long as you can mash the jump button.
Dimitri from the same game as mentioned above:
A dodongo that can climb up waterfalls and swim pretty fast. His abilities in combat is flatout biting and eating his enemies. When it comes to additional details, he can be picked up and thrown around.
BowWow the Chain Chomp from Link's awakening:
After recusing this chain chomp from some bad guys, you would be allowed to take BowWow on a walk. Probably the strongest of the animal helps because BowWow(Gender unknown) can eat and defeat most if not all enemies with one hit and is used to get in a specific dungeon.
The Crimson Loftwing from Skyward Sword:
Honestly, I don't know much about it since I've never played the game, but as far as I know, he is a means of transport.(Anyone is free to elaborate if they know anymore about this bird)
Animal helpers that appear in multiple zelda games.(Within spoiler)
Epona(From Multiple Zelda games)
Iconic in her own right and I think it's safe enough to say that everyone knows about her. She is a means of transport that can not only trample enemies, but unlike most animal helps, she allows you to still a lot of your tools.
Kaepora Gaebora from Multiple Zelda games:
He's the owl that appears in new areas to either speak of the area or share some expository info. Depending on the zelda game, he also shares advice. Not much else to say about that except he is sometimes considered a form of the sage of light or a form of the hylian king in skyward sword so there's that.
Animal Helps that appear in "A Link To The Past":(Within Spoiler)
The Flute Boy's Bird from A Link to the Past:
There isn't much to say except this bird lets you go to places you've visited by using the flute.
The Bee and Golden Bee from the same game:
Once captured into a bottle, you can release it to take down enemies for you. I hear the golden ones are more permanent.
Feel free to talk about the animal helps and share why you like certain animal helpers or whatever on the subject.