Who is the signer and guitarist with the Minnie Pearl hat that played rock and roll on Saturday Night Live or MTV in the 1990's their name had crawfish or crawdaddy in it She was an older signer?

The artist you're referring to is probably Dr. John, who was known for wearing a hat similar to Minnie Pearl's. However, if you're thinking specifically of a female artist with "crawfish" or "crawdaddy" in her name, it might be a mix-up, as there isn't a prominent older female singer from that era fitting that exact description. Another possibility is the band "Crawfish" led by a notable musician, but they were not as widely recognized in mainstream media at that time.