so true. The spider was my ONLY used pet the entire playthru. In combat. She dished good dmg, tanked a lot more than the others, had the biggest jump you could want, and could "cast web" every turn. OP compared to the weakling wolf, bear and boar. And the 1 HP Raven that was as strong as a familiar.
My suggestion: a Ranger beastmaster should have a pet that can grow in power. In the beginning, the spider shouldn't be so strong, but at level 4 it's weird that the wolf still has 11 HP, and the Raven 1 HP. It's also boring to have a pet as a beastmaster, and not have it grow properly. Even if in a nerfed way... (my experience is with DnD 2/3/4E, so I wouldn't know about Unearthed Arcana Ranger, but I guess everyone who knows about it thinks it's a better version).
