i did see serval of them already. mostly hiding under rocks ..

maybe anyone knows what it is ?

looks like a Scorpion .. or something semilar ...

any danger ?

Yes, that's Brian.

just have been told (by the Security Guard)

seems to be a Whip ... not dangerous at all ..

except of if its bite it can hurt like hell, as its has very powerful clamps

eats Worms and Roaches .. (kinda helpful)

Facts about whip scorpions

(so-called because they do not have a whip and they’re not scorpions Otherwise the description is perfectly accurate).

• The Vinegarroon, also spelled Vinegaroon, Mastigoproctus giganteus, is a type of Whip Scorpion, an arachnid that emits a vinegar-like mist containing mostly acetic acid. (Useful to carry with you on picnics, with the olive oil). The Vinegarroon is not venomous and is not a true scorpion. It is related to spiders, true scorpions, and ticks.

• Vinegarroons are carnivores that hunt at night. They use their powerful pincers to catch prey. During the day, Vinegarroons hide under leaves or rocks.

• The long, whip-like tail is used as a sensory organ and does not have a stinger (unlike true scorpions, which have a stinger at the tip of the segmented tail).

• In captivity they tend to be very aggressive to one another and it is only possible to keep them in individual cages.

• The common Thai name for them means ‘stinking scorpion’.

• Whip Scorpions range in size from 25 to 70mm in length,

• They use their long thin front legs as feelers, in much the same way that insects use their antennae.

• Whip Scorpions are purely nocturnal hunters feeding mostly on insects such as cockroaches and grasshoppers, though they also eat worms and slugs. The prey is siezed between the two pedipalps and crushed between special teeth on the inside of the trochanters (the second segment of the leg) of the front legs. The large American Mastigoproctus giganteus carries its prey back to its burrow to eat and has been known to feed on small frogs and toads.
• After mating, the pregnant female digs a special burrow with a large area at the end. When the eggs hatch, the young are white and look nothing like their mother. They attach themselves to their mother by special suckers. After a while, however, they molt and look like miniature whip scorpions. They are slow-growing and molt three times over a period of about three years.

Sounds like you are an "expert" like me! An "ex" is a has been, and a "spert" is a drip under pressure! Just kidding, but google is great!

Have seen something similar in Surin.

My Thai lady told me that they used to play with them as children.

She clamped one onto the webbing between two of my fingers.

It didn't hurt at all and was persuaded to let go without any pain.

Yes if it is the same they are harmless.

Not like an Australian Yabby that can chop your finger off.