Ringo Starr is going to voice a character called 'Fibonacci Sequins' in an upcoming run of the Powerpuff Grils show on Cartoon Network. His character is apparently the 'most famous flamboyant mathematician' in town. I remember this cartoon as a staple from when I was younger (it ran from 1999 to 2005 so I'm probably dating myself here) and you couldn't go anywhere without finding Powerpuff Girls merchandise in some store. It even won some awards in it's day and was made into an anime in Japan.
This isn't the first time that Ringo Starr has appeared in a children's program. Remember this?:
Also part of my childhood.