Ratling boss after finishing crystal mines

[ernirulez]

Hello,
I finished the sewers and then I went to the crystal mines. I completed them (getting the two gems among other stuff) and when I got out from the crystal mines... fuck! the area outside is full of ratlings and the rat boss is there with his cannon. Again!
Well, it´s ok for me, but I was wondering.. this boss respawn is normal? what is the frequency of these respawns? They appear in normal areas when you reach certain levels or you have gathered a certain number of gems? How do this work?

[Sarumorpheus]

If you defeat this boss, you'll find that...

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... he's actually the twin brother of the other ratling boss you defeated. This is revealed by uncovering a letter addressed to him by the Island Master, instructing him to gather his piRATs and take revenge on the trespassers (aka you) for slaying his brother.

[Sorez]

If you defeat this boss, you'll find that...

SpoilerShow

... he's actually the twin brother of the other ratling boss you defeated. This is revealed by uncovering a letter addressed to him by the Island Master, instructing him to gather his piRATs and take revenge on the trespassers (aka you) for slaying his brother.

Does this mean he doesnt spawn if you dont kill his brother?

[ernirulez]

SpoilerShow

Wow, I don´t remember uncovering that letter, but if that is his twin brother I really like it. +1 to the developers for these great events

[Saice]

weird I got

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All the ratlings and the trickster but not cannon rat and I straight up ran the other one into a corner and shanked him

I wonder if there is some other trigger that spawns him.

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Also I killed the trickster on the pressure plates leading to the mine and he did not drop anything.

[Sarumorpheus]

SpoilerShow

Wow, I don´t remember uncovering that letter, but if that is his twin brother I really like it. +1 to the developers for these great events

Yeah, I really liked it too. It was an awesome event and the fact that it was a minor detail shows that the developers care about the world they've created.

If you'd like to see the letter:

SpoilerShow

[ernirulez]

Nice! I haven´t found the letter yet. Do you remember where was it?

[Dr.Disaster]

Nice! I haven´t found the letter yet. Do you remember where was it?

It drops with the killed boss.

[ernirulez]

Nice, it makes perfect sense

[ernirulez]

I got the same as Salcer. It´s really weird and it might be some kind of bug. But it happened also to me that I got out from crystal mines and there were the ratling boss twin brother and his piRATs. I tried to hide in some corner to kill them one by one. What happened is that the ratling big twin brother with the cannon ball just disappeared and instead I fought the trickster, who after some hits vanished leaving nothing.
Did it happened to anyone else? Is this intended? what is the meaning of the ratling boss twin disappearing? A possibility that I thought was that it just got into the portal to the Hub, which is very close...