Is the megaraptor's Fortitude saving throw correct?

Question

I'm trying to understand whether this is an error, or whether there is something I'm missing.

According to the System Reference Document, a megaraptor's Fort save is +10.

As an 8 hit dice animal, its base save is +6 because Fort is a Good save for it, and it gains a +5 bonus on its Fort save due to its Con of 21; therefore, its total Fort save bonus should be +11.

I also checked the D&D 3.5 Monster Manual errata, and I noticed that the megaraptor has been amended, but nothing I can find resolves this particular issue. Its size was amended from Huge to Large; however, this hasn't affected its Con bonus, as both in the errata and an unrevised 3.5 Monster Manual, it is listed as 21 (+5). Its HD are also both the same.

Is the megaraptor's Fortitude saving throw correct?

Answer 1

It's incorrect

This is, indeed, an error. As the question points out, the megaraptor (Monster Manual 60–1) should have a Fortutide saving throw bonus of +11. This error remains uncorrected by the premium edition Monster Manual (2012) that incorporates the errata that makes the megaraptor instead size Large. Cooper's Compendium A–D agrees that the megaraptor's Fortitude saving throw is an error, saying

The megaraptor was downgraded, via official errata, from a Huge animal to a Large one. The changes I [i.e. the author of the Compendium, not the one writing this answer] made to the creature’s stats [in the Compendium] all stem from this change in size, with one exception: I bumped its Fortitude save up from +10 to +11 (it gets +6 as an 8-HD animal and +5 from its Constitution). (93)

So you know, Cooper's Compendium corrects most of the Monster Manual creatures that need correction. (Many, many do!) While the Compendium does still gloss over some gray areas (see here, for example), it addresses many of the Monster Manual's minor oversights like this one. I'm not associated with Cooper's Compendium, but I recommend it to any DM for whom customizing monsters is serious business.