Whatever this thing is, it has definitely never been seen before in this world.

It's definitely seeing this world, though, what with its large number of eyes. And toothy mouths. And it is taking up a fair fraction of the space in the room, because it is a swarm of floating blobs with either giant eyes or giant mouths as the major feature in their leathery gray skin.

It collectively falls a short distance before planting some blobs firmly on the ground and recovering its balance, but it still seems startled.

...well. 

The beings he's summoned before have generally taken a more...comprehensible...form, but he supposes there is no reason a visible head or limbs should be mandatory. Still, he won't be able to claim it properly unless he understands it at least a little, so he begins studying it closely to figure out how it moves and eats. And stays together, that too. 

There are no ears in evidence, but perhaps it hears by the same mechanism by which it counts as a single creature despite being composed of apparently unconnected...there really is no better word for them than 'blobs'. 

"Greetings, strange being from the outer planes," he says smoothly, while already starting to adopt the attitude of mind that will let him claim the creature as part of his hoard. This is his, no matter how strange it appears. He summoned it to be his servant, and it answered his call, therefore it belongs to him. "I am Zuragazh, and I have summoned you here to be my servant and carry out my will." 

The blob-swarm takes a good look around while condensing itself into a form more arrayed than 'teleported startled ravening horde'.

After he speaks, it speaks. Incomprehensibly. Its voice is oddly like that of a much smaller creature, for all that it is loudly in concert from the many mouths.

A language barrier; wonderful. Zuragazh was just thinking about how such things were missing from his life. Fortunately, one of his bound spirits should be able to translate.

First, to make sure the blobs won't simply walk—roll? float?—out of the door the moment his back is turned. He speaks the command word that activates the magic circle embedded in the floor, and the area surrounding the middle of the swarm is flooded with cold blue light as the runes begin to glow.

That done, he turns to look for the right bottle. Not all of the blobs are inside the circle, but the ones that are should be prevented from leaving before he is ready. Once he's finished claiming the creature, that won't be a problem, but his claim doesn't seem to be taking at the moment.

It's almost as though it's being contested by another dragon. But what self-respecting dragon would let part of their hoard go wandering off to the outer planes? 

Some of the blobs on the outside of the circle touch it — and pause, startled, and pass through anyway. Then they reverse direction and the entire structure inside the circle hurriedly leaves it.

It speaks again. Parts of it head toward the exits.

Zuragazh feels the binding fail and whips back around just in time to see the last blob leave the circle. What—oh, of course, the blobs clearly count as a single creature for the purposes of this spell as well as the other. Well, that's inconvenient.

Abandoning his search, for now, he pounces on the nearest blobs and attempts to pin them in place with his claws. These things are his and they are not leaving! 

One dodges. The other is partially grabbed, but not pierced — it feels squishy but extremely tough-skinned — and another toothblob flies in and butts his arm away.

And they're still not even slightly registering as part of his hoard, after all this effort he's put into keeping them.

He snares that blob with his tail, instead, and lunges at the one that butted him. Time to find out how well tough skin holds up against a dragon's teeth. 

The one his tail went for squeezes down and bulges and pushes off the encircling tail, then joins the swarm flying for the exits.

The other yields slightly to teeth before abruptly becoming as rigid and impenetrable as the warding circle should have been.

...ouch. He holds onto it with what slight grip he has, but lets the others go; they're no longer worth the effort of pursuing them.

True, he may have just unleashed an abomination upon the world, but it doesn't seem like it can hurt him or it would have done so by now. He's not too worried about everything else. 

Having made its point, the last blob wriggles and politely slips out of his jaw.

Now, which one of those exits is actually leading somewhere useful like the outside? If there is an outside.

There is indeed an outside at the end of one of the tunnels. The other tunnels lead to more treasure rooms, a pit full of bones—mostly not humanoid—and an underground stream.

Unfortunately, the lair's entrance is halfway up the side of a mountain and overlooks a sheer drop, making it completely inaccessible to anything that can't fly. 

Of course he can fly — escaping is not the time to build some wings but there's still an opportunity for anchoring. A mouth and an eye unit drop down to the bottom, while the rest of the swarm finds its way around to this path without bothering the large rude person again.

Braced against the tunnels and the ground below, he heads down in a flock.

The ground at the bottom is jagged and pointy and devoid of any sign of life. Below him, the mountains fall down into hills, and a river winds its way out from their base and across the plains. 

The night sky is lit by two moons, both full. There are other lights on the horizon, somewhere downriver. All is quiet. 

Two moons. Uh-huh that sure is a thing along with the force field and the teleportation and the absence of any radio at all.

He finds some jagged pointy vague cover against line-of-sight from the mountain, then sets about reforming what material he has available into an adequate flying form.  —let's make that three separate forms, because being partly outside that circle seems to have been possibly highly valuable and there might be more stuff like that. With the volume of his ex-monster-costume which he's not throwing out just yet, these bird forms end up being ten feet tall.

He takes off by jumping upward off the inconveniently rough terrain, and heads downriver. Slowly, and well-lit, and neither particularly high nor too close to terrain; he doesn't know the flight conventions or what kind of traffic to look out for here. He occasionally checks the ground for anything interesting and not as visible as the Cliché Signs Of Civilization ahead.

Nothing interesting presents itself unless he's the sort to be fascinated by the subtly different types of fish in the river. 

The lights in the distance resolve into what looks like a settlement of some kind, which as he gets closer reveals itself to be a sizeable town or even a small city. 

Weird architecture, but that's to be expected. Anything plausibly an IF YOU NEED EMERGENCY ASSISTANCE OR ARE JUST LOST, LAND HERE kind of place?

There's a nice big empty square surrounded by reasonably official-looking buildings, does that count? 

It looks like there's enough space for that dragon he met to land without knocking anything over; Thanjen shouldn't have any problems. 

He has no idea how irregular his situation is. Is there something more tourist-information-y? Or rather, is there a part of the city that looks like where visitors go in, big signs and decorative walkways and whatnot?

There's a port on the river's edge? It seems more shipping-focused than touristy, though. 

As he's pondering where to land, a winged shape, gleaming white in the moonlight, launches itself upwards from a rooftop and circles around to meet him in the air. It's much smaller than the last dragon he encountered, probably about human-sized if one discounts the wings and tail. 

Perhaps this one will be friendlier. He does not fly away.

Keeping a safe distance from the strange large flying creatures, the white dragon calls...presumably a greeting...in his general direction.

Unfortunately, Thanjen has not mysteriously picked up the ability to understand this language since the last dragon who tried to communicate with him. 

Perhaps being equally incomprehensible and taking a following position will get the relevant message across.

...yeah, alright. 

The dragon leads the way down to the big empty square, lands, and knocks on the door of one of the official-looking buildings. He isn't taking up very much of the available landing space; there's still room for Thanjen.