This creature crept out from the back of an old bookshelf in our living room, first we thought it was a cockroach, but then we noticed that it has this needle like tail, and a couple of pinchers like a scorpion. And it burst out acid odors when it feels threatened.
Location: West Java, Indonesia

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I cannot tell you the species I am afraid, but I can tell you that it is not an insect. One of our invertebrate experts may correct me but I am 99% sure this is something commonly called a "whip scorpion" or "vinegaroon". These are animals in the Thelyphonida order, which is a part of the arachnid class (i.e. the group containing spiders and scorpions among other less known beasties).

I'm guessing it's not alive after your enconuter, but to reassure you it was harmless. It's defense was that vinegar like chemical, a slight spray. Good against other inverts, pretty useless against us.

As per alistair, not an insect, you can find more info on the 27 species known from Indonesia here, which will get you some possible names to search about futher. The front palps are the strong parts on the front, for crushing prey - purely mechanical. The "tail" is a flagellum - a fine sensory structure that is soft with fine hairs.

No venom, not danger, just tough things than use strength - but not strong enough to resist us humans that dislike them. No need though, harmless and wonderful creatures.

http://museum.wa.gov.au/catalogues-beta/whip-scorpions