User blog comment:Kogath/Monster Hunter X Discussion/@comment-5963861-20150606102101/@comment-6050823-20150606123641

I noticed it the very first time I watched the trailer...

Nibelsnarf was the first one I noticed, I was kinda shocked they put a Leviathan in the Old World but I later on learnt that you get Agnaktor parts from the Old World plus considered the whole Kuarusepusu. The Meowster Quests didn't help either!

Forest and Hills / 森丘 :

Gargwa, Kecha Wacha, Rathian, Nerscylla, Seltas Queen, Zinogre, Dalamadur, Yian Kut-Ku, Congalala, Basarios, Seregios, Gore Magala, Chameleos.

Volcano / 火山 :

Slagtoth, Tetsucabra, Rathian, Rathalos, Rajang, Teostra, Akantor, Yian Garuga, Brachydios.

Desert / 砂漠 :

Rhenoplos, Tetsucabra, Nerscylla, Seltas Queen, Tigrex, Shagaru Magala, Cephalos, Seregios, Monoblos.

Snowy Mountains / 雪山 :

Bnahabra, Zamtrios, Tigrex, Rajang, Kushala Daora, Kirin, Khezu, Lagombi.