What is it? Kind of looks like a weird hairy dog with no face. This is in fact a Flannel moth caterpillar and they get quite active during Springtime. If you see them, leave them alone.
Under their long wig lie rows of venomous spines that will inject a nasty toxin. These are one of the more dangerous insects in America. Symptoms vary from a rash irritation to headache, nausea, severe pain and respiratory issues.
Bottom line: Look but don't touch. :)