He and Jerry wrote one of the most beautiful songs in the English language. Ripple.
https://www.youtube.com/watch?v=671AgW9xSiA
From Wikipedia: Hunter was born Robert Burns on 23 June 1941 in Oceano, California. In a 1973 Rolling Stone profile of the Grateful Dead, Charles Perry reported that he is a great-great grandson of noted Romantic poet Robert Burns.
Sounds interesting...
Here is sort of a peerage of Robert Burns descendants, and it does not appear that an unbroken line of male descendants survived to end up with a Robert Burns as the great-great grandson of Robert Burns the poet. Not to mention that it would take a few more generations to bridge the gap.
https://www.burness.ca/g0/p92.htm#i919
It was a nice story, though.