How do I handle baby creature followers/pets in Out of the Abyss?

Question

I am new to DMing, and I am running the official Out of the Abyss adventure.

My players found some eggs. When the eggs hatched, baby hook horrors popped out. The players saw them and decided to try to tame them. Knowing this would be hard, I thought, "Hmm... maybe I could just give them a high DC on Animal Handling to tame or at least convince them that they are their parents." (One of them had previously dismembered the parents to the point of being un-recognizable, so the babies wouldn't think they were the parents).

So, I gave a DC of 25. This was especially hard because the highest Animal Handling bonus in the party was a +5, so they either needed to roll a 20, or use Inspiration. (We play with a house rule that inspiration=automatic 20, not just advantage.) They all just used Inspiration to succeed.

So, should this be possible? I know that Animal Handling is used to calm creatures, but the players were also the first thing they saw. I found nothing in any 5e rule books saying anything about this.

My main problem is that I only thought of asking forums after I said that it worked, so I don't want to be evil and just bluntly take what I said back.

Answer 1

You asked:

"Hmm... maybe I could just give them a high DC on Animal Handling to tame or at least convince them that they are their parents."

and

So, should this be possible?

Yes, absolutely, and there are specific rules for it for this specific scenario.

Out of the Abyss, the scenario you're playing, under Chapter 2, 4. Hook Horror Nest, says:

The infant hook horror that emerges imprints on the first creature it sees. It thereafter follows that creature around like its parent, demanding to be fed. If the characters manage to keep the hook horror alive, it eventually reaches adulthood after six months. Track its growth using the Hook Horror Maturation table.

So, yes, your PCs now have hook horror "pets", or at least little hook horrors following them around wanting dinner and making messes on the floor. I'm sure they'll have fun walking them in the park.

Of course, according to the MM, grown hook horrors are pretty fierce beasties. They'll eat your neighbors' pet tiger for lunch and their dog for a snack, they've got the hit points of an elephant, they're much smarter than the average bear, and they've even got their own language. Heck, they're smarter than hill giants, not that that's saying much. Not exactly a pet you see lined up at the vet's for a checkup, although I bet you and your hook horror wouldn't have to wait long to see the doc, and if so, the horror could fix that little problem in a jiffy. Your PCs are in for a ride.

And eventually your PCs are going to ask about it and you're going to have to rule if hook horror language is nature or nurture, because if it's nurture they aren't going to grow up "speaking" their language, and if it's nature one of the PCs is going to want to know if they can learn to "speak" hook horror.

And of course your PCs are going to want to train their hook horrors to attack on command. That may end up being less of a command and more of a negotiation.

Answer 2

In your case, the adventure already describes how "taming" the baby hook horrors works

Pages 33-34 of the Out of the Abyss adventure describe the hook horror nest:

The sandy floor of this cavern holds a clutch of four 1-foot-diameter eggs with rocky outer shells, all half-buried in a shallow pit. These are hook horror eggs, and any character that touches an egg can feel it trembling.

Each hour, there is a 10 percent chance that one of the eggs hatches. The infant hook horror that emerges imprints on the first creature it sees. It thereafter follows that creature around like its parent, demanding to be fed. If the characters manage to keep the hook horror alive, it eventually reaches adulthood after six months. Track its growth using the Hook Horror Maturation table.

The table that follows provides the basic stats for each stage of the hook horror's development.

In essence, if you run the adventure as written, no Animal Handling checks are needed at all. There are four eggs; each hour, there's a 10 percent chance of one of them hatching. (Ostensibly, this would be simulated by you rolling a d10, and having an egg hatch on a roll of 0 - or 1, or any other specific number of your choice.)

Once the egg hatches, the baby hook horror will imprint on whoever it sees first. If a particular character is interacting with the eggs at the time, it'll probably be that character; otherwise, you can probably pick the nearest party member (or a nearby character within sight at random) for it to imprint on.

Once it has imprinted on a character, the baby hook horror will follow that character around "demanding to be fed" (as an animal would). If it's kept alive and fed, it'll continue to grow.

No checks are necessary for the imprinting to work. Anything beyond those guidelines is up to the DM.

Answer 3

Most of what you've done is well within the "Improvise An Action" suggestions of the PHB and DMG. However, you have made one significant rules mistake...

"Natural 20" is not a valid Difficult Class.

DC are a target number for an ability check. It could be 20 or even higher for something you want to be very difficult, but specifically requiring a Natural 20 is not appropriate. In D&D5e, "Natural 20" only has significance for attack checks - it's a critical hit. For any other kind of d20 roll, 20 is just a big number.