there are many. i can't think of them all of the top of my head.
but i know in forest temple the mini boss is a baboon, in death mountain it is a large and angry goron, in lakebead temple it is a large toad sort thing, in arbiters grounds it is a skeleton sort thing with a large sword, in snowpeak ruins it is an armored type of creature with a ball and chain, and i forget the other ones...sorry, that's the best i can do
hopefully somebody will improve this answer :P
In "The Legend of Zelda: Twilight Princess," to find the Boss Key in the Faron Woods, you must first navigate through the Forest Temple. Inside, solve various puzzles and defeat enemies to progress. The Boss Key is located in a chest that you can access after defeating the mini-boss, the Stalfos. Once you defeat it, you can unlock the door that leads to the boss room.
in hyrule castle
there isn't one...
My opinion is ganondorf's first phase puppet princess Zelda
The last level on Zelda twilight princess is hyrule castle where you face the final boss ganondorf.
It's on the map.
beat the boss
deffet the monkey mini boss
Argorok the Dragon
The mirror of twilight is in the desert. you gain access through the mirror of twilight after defeating the boss of the desert temple.
Find the big key.
in the main room