I don't think it is a scorpion, looks more like a bad a$$ mut-ant, ant, get it:cheeky:?
But at 4" long, that is some huge ant. Scorpions have stingers and I can't see a stinger. I actually got stung by a scorpion abput 20 years ago and it was pretty easily defined, just as is typical. With something like only 1/4 of the worlds insects identified, or infact the animal kingdom it is worth capturing these things and trying to have them identified, you never know.:glasses:
Actually following Katias post I had a look at those alacran and there are some weird looking subspecies it could well be.