- Boar: I think this one is broken, the boar charge simply does not work nearly as well as it should, I don't know if they fixed it in patch 3. I wanted to use it so bad but this summon it was not worth it at all. If this skill was fixed and the hitting chance was slightly higher (boars are agile) this one would be great.
- Bear: Works great
- Giant Spider: Works great and it's my favorite, the web casting ability works great for massive battles
- Raven: I think that not every animal companion should be useful in fights, some could be more useful outside of battles, interacting with the world, so I feel this one could use the flying ability in a more meaningful way. You cannot push things around like the other animals can, so you can reach some high grounds but cannot do anything with the things you find there. Maybe if you could interact with light itens and characters things could become interesting, making this summon more useful to have by your side, like picking up a key somewhere high and bringing it to you. talking about battles, maybe picking up some small goblins / itens and letting them go during flight would be awesome. Rend vision + 1 hp is definitely not worth it.
- Wolf: Between the goading ability + HP of the Bear or the web + poison dmg of the spider there's really not a reason to choose the wolf. The prone ability of the wolf is not worth it because of it's low % chance, this summon ends up dying faster than you could use the prone ability effectively. I think the wolf should have some more agility advantages besides the Jump/Disengage skill. Maybe if it had some higher hitting chance + extra low bleeding dmg OR higher hitting chance + attacking earlier in a fight could make me think about choosing this one over the bear or the spider.
Edit: During my gameplay I thought the wolf had higher chances of finding hidden things but turns out the chance seemed pretty even between all animals when I used them all at the same places. Maybe this would be something unique to the wolf, having a stronger smell gives him higher chances of finding stuff.
Now one really important question, why does the summon ability only works outside of battle? In baldur's gate 1 and 2 was like this as well? Because I could not really see a motive for this, why wouldn't a mage ou a hunter be able to summon during battle? If you wanted to make things a little bit harder for summoners to fight, maybe just being able to summon once or tooking 2 turns to summon something would work. i don't really see the reason here (don't know if things changed in patch 3)