So I messed around with some Master Rank and High Rank online quests just joining SOS stuff and beating quests in like 10 mins getting loot. Then I tried taking on BARIOTH.
Since I never fought Barioth in GU/XX I thought he was just some sabertooth tiger monster, no big deal.

...no he's a giant leaping fucking Tigrex kinda dragon with INSANE ICE TAIL swipe, crazy movement ice tornadoes, huge range fast shoulder check, etc....
I tried him single player for a bit with slow hammer and at first was getting wrecked, then found some safe spots and did ok for a while then died.
Got in a 4p match and it was easily the most intense and challenging monster I've fought in all of World + Iceborne as well as GU/XX. Fight was pretty epic and we had 2 faints and I was doing a lot of run in and get some hits and run away and heal tactics so I didn't wipe our group. I took out both his front legs which was supposed to slow down mobility but he still seemed as fast idk. Then our sword guy took off the tail which definitely helped on the giant tail swipes. We kept the pressure and cleared around 33 mins.
Crazy good fight. Is Baroith considered an Elder Dragon because it sure seemed Elder Dragon material. I can't believe the moveset he has with that speed and wall climbing and range. Insane monster fight.
lol, just googled him in GU/XX and he's like a tiny little baby. They dramatically beefed him up in Iceborne. He's so much bigger so he hits in a much much bigger radius and he also seems more aggressive and faster in Iceborne compared to this video.