I mean, when you are visiting countries with subtropical - almost tropical - climate you will have to expect any kind of creep, spiders, cockroaches, beetles, scorpions, ants, termites, lizards, geckoes, snakes, you just name it - and so is Thailand as well.

With all due respect for your fobies (I know this can be very bad), I'm sad to say that I think you will have to give your plans about visiting Thailand - and countries with a similar climate - a very serious second thought, because you will meet several of these species everywhere, indoor even at the most clean hotels or restaurants, and outdoor whereever the creep can find a living.