Housemate and I took a different path in Grauberg possibly to most people. We saw no Peiste on the path or chiggoe/gnats. We went H-8 then West and South to F-10 in order to slide down the rivers.

Mobs we encountered in the narrow path there:
Ajattara: A war wyvern type mob, extra decorations and different colours (more vibrant). Aggressive to sight. Lirianuin (housemate) went ahead at one time and walked past one without Sneak on.

Grauberg Hippogryff: Even Match to 75s. Believed True sight, so we avoided them, but their aggro range seems as short as their cousins in Riverne. It is probably possible to learn Hippogryff moves on them as a Blue Mage without access to Rivern Sites.

The clearing just before the river has several Ajattara and hippogriffs, so it's best to make sure sneak/invis will last you till you're in the water to recast (there's also a tunnel opposite the river where you can safely recast, we believe there is no undead pop there at night but caution is advised).