TL;DR: low level party's DMPC goblin gets eaten by a dragon. While in the stomach, she slams a Bag of Holding into a Bag of Holding. Should the tear to the Astral Plane transport the entire dragon, or just it's guts? Looking more for opinions than strict rules.

I have an idea for my campaign to sort of... fix my problem of a DMPC I'd like to remove for a short period.

My parties companion, a goblin, aptly named Goober, has become a bit of a crutch. They use her rogue abilities far more than they need, so I'd like to remove her for a bit, letting the low level party find their own strengths.

The Githyanki in the party has a backstory involving dragon riders and a questionable crèche. I was thinking, when things seem dire, have the goblin, who does have both the parties BoH and her own for explosives, get eaten/swallowed. While in the belly of the beast, toss one bag in the other and open a tear to the Astral plane.

This lets her return later, potentially. But my big question is: would it be better, or more cool, or absurd, to have the tear in reality just rip out the mid torso of the big dragon, turning the tides of battle? Or should the dragon be transported whole in the sense of "rules"?

Thanks in advance!

As written, it transports the whole dragon. The dragon's guts are not a creature. 

The DM can, of course, do whatever they like.There's also no guarantee that this operation will remove the character from the stomach.

There's also a whole bunch of issues around the handling of DMPCs or long-term NPCs that I'm not currently braining well enough to discuss well.

Short version:

• I look askance at planning out a big blaze of glory, even if it is to remove the character. You're stealing the players' thunder.
• Yes, even if it's just a contrivance to remove the character. The players can't know that.
• Does this sidekick just happen to have two bags of holding, or are you also swiping the party's loot stash?
• There's more, but see above lack of brain.

I say that whichever is funnier. Most of my campaigns say "Screw you!" to the rules and do more comedic idiotic stuff. Personally I would do the guts disappear and the dragon just ragdolls to the ground, dead.

Well, given that dragons do not have the swallow whole action, the swallowed character is dead and can take no actions.

For RAW, see both pantagruel and jl8e’s posts, I’d say. I would add that transporting the guts without the rest of the dragon opens up a number of possible problems with, essentially, targeting body parts. It’s a can of worms you’d be opening.

But if you’re just looking to have the DMPC leave, you can just do that. They stop in the next town, say something like, “well, folks, I have a personal matter to deal with and I need to go.” Then they leave. They can still come back later.

No need to overthink it. 

All decent points, thanks for the quick replies.

As I said, I'm not really concerned with RAW in the case of it ruining Rule of Cool. 

Being a goblin, I figured they could easily be swallowed whole by a big creature like a dragon. And the DMPC has the parties BoH because of no player wanting to track capacity. Their personal BoH is an Artificer replication. If they had some particularly valuable items inside, I probably wouldn't do this, so they don't lose them.

I suppose the DMPC could just stay back at their stronghold to run the tavern or go off on personal business... but that doesn't have the same impact. Plus, returning as an Astral Sea Pirate would be awesome lol.

Thanks again!

I wouldn't set the precedent that a Bag of Holding explosion can take only part of a creature with it, especially if your party has an Artificer that can make bags of holding. I promise if you show them that move, it will not be the last time you see it.

Quote from jl8e >>

As written, it transports the whole dragon. The dragon's guts are not a creature. 

The DM can, of course, do whatever they like.There's also no guarantee that this operation will remove the character from the stomach.

There's also a whole bunch of issues around the handling of DMPCs or long-term NPCs that I'm not currently braining well enough to discuss well.

Short version:

• I look askance at planning out a big blaze of glory, even if it is to remove the character. You're stealing the players' thunder.
• Yes, even if it's just a contrivance to remove the character. The players can't know that.
• Does this sidekick just happen to have two bags of holding, or are you also swiping the party's loot stash?
• There's more, but see above lack of brain.

 Fully agree with this. Using the DMPC like this to take the spotlight isn't good IMO. Especially when you are taking the players' magic items to do it - no matter if it's "just" an Artificer replication, or if "nothing expensive was inside". It's still taking the items from the players and using them to make your own character do cool things to save the day. That's what the PCs are there to do; instead, they'll just kinda sit and watch as you create the problem and then solve it all on your own. 

Were there items at risk of being lost, I'd probably rule they spill out like when the bag rips. As for taking away from the players, the situation is practically unwinnable. Sending the highest CR dragon away at the cost of the DMPC is to level the playing field and turn the tides. A sacrifice to turn a dire outcome into clawing victory from defeat sounds pretty rad to me.

But I guess sending them on a personal quest or staying behind to run the tavern works... though it feels severly lackluster. Removing a liked character for an extending period feels like it needs to be a memorable event.

I suppose I could just unalive their beloved little Goblin...

So often people talk about BoH + BoH as a "nuke" or an "explosion" when it is not. It is a teleport. The affected creature is totally unharmed, it is just whisked away to the Astral Plane. In no way does this need to be the end of that creature's story, and in my campaigns doing this to the BBEG would just ensure he eventually returns for payback with some powerful Astral allies.

My thoughts exactly. I'd like to remove the DMPC in a spectacular manner, but allow them to have the option of returning. Sending them off to the Astral Plane sounds like a great plan!