Song: Zinogre Theme
Game: Monster Hunter Portable 3rd (Also every iteration after it)
Composer: Masato Kouda
I started playing Monster Hunter a few years ago when Monster Hunter 3 Ultimate came out. Somehow I ended up falling in love with the series and have been playing it ever since. It's an odd series, which is definitely not for everyone. It has a high barrier to entry, and has a lot of repetition. What's cool about it is that each one of the monsters you fight is wholly unique. They have their own patterns and movements that you need to learn in order to take them down effectively. That's why I tend to describe Monster Hunter as a series of boss fights.
Like their abilities and looks each monster also has a unique theme. There are tons of themes to choose from, but the one I always think about it the theme of the Zinogre. It's a crazy electric wolf and I love fighting it. Not only is it one of my favorite monsters in the series, but its theme is great too. It's appropriately intense, and always makes me feel like I'm taking part in an epic struggle with the beast.
Here's a picture of a Zinogre for reference: