Wyvern dragon cohort D&D 3.5

[Crow_Nightfeath]

So I'm looking at the table for dragon cohort and it says a wyvern is an ECL 12, but the wyvern has 7 HD in the Monster Manual and the Draconomicon says it has a level adjustment of +4. I'm no math expert, but isn't 7+4=11?

[InvisibleBison]

Your math is correct, but the rules about cohorts in the DMG (p. 106) establish that your cohort must be at least 2 levels lower than you.

[Extra Anchovies]

So I'm looking at the table for dragon cohort and it says a wyvern is an ECL 12, but the wyvern has 7 HD in the Monster Manual and the Draconomicon says it has a level adjustment of +4. I'm no math expert, but isn't 7+4=11?

ECL always assumes the creature has one class level. I'm not sure how this interacts with dragon cohort, but I think it means that the ECL 12 wyvern has one class level, and continues advancing by class rather than by racial HD.

[Crow_Nightfeath]

so with the dragon cohort feat, which treats their level as 3 less, you could actually get a wyvern when you are level 10? because 11-3=8 which is 2 levels lower than 10.

[Crow_Nightfeath]

ECL always assumes the creature has one class level. I'm not sure how this interacts with dragon cohort, but I think it means that the ECL 12 wyvern has one class level, and continues advancing by class rather than by racial HD.

None of the others on the list are treated that way, wyrmling silver dragon has 7HD +4 level adjustment and is an ECL 11 on the table. actually there is another one that is weird pseudodragon is a 2 HD +3 level adjustment creature, but is an ECL 4 on the list