Epic Animal Companions BAB and Save Increases

[Oddstar]

I have a question about the progression of animal companions at epic levels. According to the SRD, a druid's (or ranger's) animal companion continues to improve when the druid gains epic levels: https://www.d20srd.org/srd/epic/classProgressions.htm. According to the PHB, "[E]xtra Hit Dice improve the animal companion’s base attack and base save bonuses." Here is my question: does an animal companion at some point stop gaining base attack and base save bonuses and instead start gaining epic attack and epic save bonuses? If so, does this happen when the druid hits level 21, when the animal companion reaches 21 HD, or the animal gains its 21st hit die as the druid's companion? I would have thought that there would be clear rules on this somewhere, but I have not been able to find any.

[Soranar]

I have a question about the progression of animal companions at epic levels. According to the SRD, a druid's (or ranger's) animal companion continues to improve when the druid gains epic levels: https://www.d20srd.org/srd/epic/classProgressions.htm. According to the PHB, "[E]xtra Hit Dice improve the animal companion’s base attack and base save bonuses." Here is my question: does an animal companion at some point stop gaining base attack and base save bonuses and instead start gaining epic attack and epic save bonuses? If so, does this happen when the druid hits level 21, when the animal companion reaches 21 HD, or the animal gains its 21st hit die as the druid's companion? I would have thought that there would be clear rules on this somewhere, but I have not been able to find any.

you reach epic levels when you reach character level 21

Same for your animal companion: it's not when you reach epic levels that it becomes epic, it's when it reaches epic HD (21+) that it reaches epic levels.

if you google epic, you should get the definition from the SRD 3.5

[Tzardok]

Creature hit dice continue to accrue BAB and Saves normaly, even beyond the 20th hd. You can see that from other creatures with more than 20 hd like great wyrms, night crawlers or solars.

[Oddstar]

Creature hit dice continue to accrue BAB and Saves normaly, even beyond the 20th hd. You can see that from other creatures with more than 20 hd like great wyrms, night crawlers or solars. I know, but those tend to be creatures that naturally have that many hit dice, which seems different to me somehow. But your answer makes sense.

[Biggus]

Animal companions' BAB and saves continue to increase normally at epic levels:


Your base save bonus does not increase after your character level reaches 20th. [...]

Similarly, your base attack bonus does not increase after your character level reaches 20th.


For this reason, the rules establish a cap on a character’s base attack bonus, because the base attack bonus determines the number of attacks per round a character can make. After 20th level, your base attack bonus never improves. You gain epic and other bonuses to your attack roll, but these don’t ever increase your base attack bonus and thus never grant you additional attacks. This limit doesn’t apply to the base attack bonus derived strictly from a monster’s Hit Dice. For instance, a titan with 21 HD using the monster advancement rules in the Monster Manual has a base attack bonus of +21.

(Italics mine)

What isn't made clear as far as I know is at what point animal companions are able to take epic feats; is it when they reach 21HD, or when their master reaches level 21? I play it as the latter, but I suspect it's intended to be the former (ELH monsters gain access to epic feats at 21HD).

[Oddstar]

What isn't made clear as far as I know is at what point animal companions are able to take epic feats; is it when they reach 21HD, or when their master reaches level 21? I play it as the latter, but I suspect it's intended to be the former (ELH monsters gain access to epic feats at 21HD).
I can see both sides. Your point makes sense, but, on the other hand, it would be odd for a druid's companion to gain epic feats before the druid himself.

[Biggus]

I can see both sides. Your point makes sense, but, on the other hand, it would be odd for a druid's companion to gain epic feats before the druid himself.

Are there are any 21HD+ creatures which can be animal companions? None of the standard ones are more than 18HD but there might be some in other books I don't know about.