Wildlife Spotting

I found this odd creature on my sunbed in northern Crete, west for Heraklion (just sand and sea within 20-30 meters). It looked like a mix between a crab and a spider, but I think it was able to move down hanging from a thread. I didn't notice any web though. It seemed to have a crab-like surface on the top of it, but since it might have been poisonous, I did not touch it. It was yellow-ish with a nice pattern, and very fascinating!