This is a Cleo mod that makes the Yeti appear in Mt. Chilliad. In Misterix Mod, the Yeti can be found but always in the same place. There's a big difference in this mod. There are 8 different places where the Yeti may appear, these are randomly chosen.
It stands still until you attack it, or get near of it. It may be a trouble to find it because it's hidden between the trees, bushes, and so. See the mod here:
I include an image showing the 8 locations where the Yeti can appear. Search carefully!