Winter's Mount

(Frostburn, page 50, DnD 3.5)

[General]

Your special mount is native to the frostfell.

Prerequisite

Special mount ability

Benefit

Your special mount gains the cold subtype. It gains immunity to cold, but has vulnerability to fire, which means it takes half again as much (+50%) damage as normal from fire, regardless of whether a saving throw is allowed, or if the save is a success or failure. Your special mount is also hardier than a nonfrostfell version; it gains a +2 racial bonus to Constitution.