This is the Io moth caterpillar, I discovered it this weekend in Mart, TX while visiting family. My boyfriend doing some yard work for his grandparents this weekend and while climbing a ladder, his hand smashed one of these guys and his hand stung quite a bit. His grandmother said they are new to Mart this year and have been on the news because of that and their peculiar sting. They are native to North America and are part of the Saturniidae family. The spikes that cover it are connected to poison glands. The sensation is similar to a bee or wasp sting and the pain can last several hours. To treat this sting, you place tape over the affected area and strip off over and over, to remove the spines and poison. Adults have a wing span of about two to three inches, with females being a dark brown-purple color and males a distinct yellow color.
my iNaturalist post can be found here.