Looks good.Shade said:Skills: *They have a +4 racial bonus on Hide checks when in forest environments. This bonus on Hide checks increases to +8 when the linnorm is immobile.
Also good.Shade said:Sound Imitation (Ex): A forest linnorm can mimic the sound of injured animals, anytime it likes. Listeners must succeed on a DC 19 Will save to detect the ruse. The save DC is Charisma-based.
I vote for CR 13.