How to farm for the legendary jellyfish at the top of the mountain for the trophy effectively? /u/PeppermintButler17 Monster Hunter: World

I know he only spawns at night with clear weather, but do I have to climb the mountain everytime? Can I see him from the ground? Why dies the meal that gives feline zoomaster not always give me the skill? Any help is appreciated!

I know he only spawns at night with clear weather, but do I have to climb the mountain everytime? Can I see him from the ground? Why dies the meal that gives feline zoomaster not always give me the skill? Any help is appreciated!