Found it on a creek floating in the water. It does happen to be dead with this weird red rash or something on its stomach what is it?
This is a caterpillar of a sphinx moth (family Sphingidae); likely an Abbott's sphinx moth. Older caterpillars of this species lack the typical 'horn' of most sphinx caterpillars, and can be highly variable in their color patter. See https://www.butterfliesandmoths.org/species/Sphecodina-abbottii for some examples.