Animal Companion optimised for dungeoneering

[MarkB]

My 12th-level druid is about to acquire a new animal companion as the party prepares to venture into the depths of Khyber, Eberron's underdark. The base creature will almost certainly be a dire bat, but my DM is being fairly generous in allowing improvements to be made to it at the cost of putting it on a higher-level companion list.

Our party, via a combination of race, spells and items, all have Darkvision, so we can expect to be traveling in darkness a lot of the time, to avoid giving ourselves away. That's one major reason I chose the dire bat, since its blindsense makes it not entirely disadvantaged in pitch darkness, but I would like to try and improve upon that aspect, in particular.

Are there any templates that can grant an animal darkvision or similar sensory abilities without changing its type?

Alternatively, are there any feats which can upgrade a creature's existing blindsense to blindsight?

Are there any other enhancements that would make a dire bat more suited to a subterranean environment? So far, I'm looking at the Dungeonbred template from Dungeonscape, for improved compactness.

 

[Gerion of Mercadia]

Check out the rules in the later WotC MM's about the Desmodu and their bat breeding program. Got to pull out the books for specifics, but it's all I can think of off hand.

 

[HeavenShallBurn]

Check out the rules in the later WotC MM's about the Desmodu and their bat breeding program. Got to pull out the books for specifics, but it's all I can think of off hand.

It's in MM2, just after demons and before devils

 

[thompgc]

Could always go for a Horrid creature (template in the monster section of ECS)
Has the druid list there - a horrid bat is level - 6
Could also go for magebred
I'd probably try to get a magic item of some sort to the animal darkvision

There are also feats in the ECS that expand what you can have as an animal companion

 

[Jack Simth]

Belt of Dwarvenkind, 14,900 gp (if you can convince your DM that a Dire Bat would have enough of a waist to put it on). Grants Darkvision and +2 Con, and +2 resistance vs. Spells and spell-like abilities, all on one slot. Actually a bit of a price break; a +2 Amulet of Health costs 4,000 gp, a +2 Cloak of resistance costs 4,000 gp, Goggles of Night cost 12,000 gp.

Reduce Animal on your Dire Bat for getting it through medium-sized dungeons.

Potentially, Natural Bond (a Feat for you) to mitigate the level adjustment (+2 HD and all that entails, +2 Natural Armor, +1 Dex/Str, an extra bonus trick, and a bit of advancement on special abilities).

Oh, and don't overlook the Dire Badger. It's got this nifty clause about leaving a useable tunnel....