After some research, I found that the vast majority of D&D players agree that an owlbear is not an animal. It is a monstrous beast. Therefore, the majority agrees that Speak with Animals and other animal-related spells should have no effect on owlbears.
This said, I think that it makes more sense to have Potions of Speak Monstrous Beasts (replacing Potions of Speak with Animals) or a magic item of Speak Monstrous Beasts that the player could use to actually have the conversation with the owlbear mother that is currently already in the game. I like the dialogue. It's fun. I don't want to remove it from the game. However, I just think the distinction should be made between animals and monsters. This also gives more value to the Potion. If druids and rangers can't even use their Speak with Animals to speak to creatures like the owlbear, and you can only speak to the owlbear using a Potion of Speak Monstrous Beast (again, replacing Potions of Speak with Animals), then the potion and/or magic item with the same spell has more value. Suddenly, even the ranger and druid might keep the Potion of Speak Monstrous Beasts in their inventory because they know that the only way to talk to the owlbear and/or the Spider Matriarch and/or the Spiders in the Goblin Camp pit, is with said potions.
SPOILERS!!! Speaking of this, I think some work needs to be done so that the players can actually talk to the Spider Matriarch. I had this idea that my Llothsworn Drow Battlemaster would actually want to try to be friends with the Spider Matriarch as opposed to fighting her and trying to kill her. So, again, it would be awesome if there was some way for PCs to gain the ability to Speak with Monsters or whatever they want to call it. Then, as my Drow makes her way through the spider's lair, maybe she could talk with the Spider Queen and her minions rather than fighting them. After all, isn't the Spider Matriarch a follower of Lloth? Therefore, shouldn't they be allies?
