The most frustrating monsters to encounter as a PC...besides rust monsters

[Willie the Duck]

Ah, ok. The source I was using had it listed wrong.

Still kinda sucks that something can deal vile damage that much earlier than the party can heal it.

Well, that's the problem with templates in general--what they provide (and thus what they should do to CRs) can really vary in potency depending on what you attach them to.