The 1968 NBC series THE NEW ADVENTURES OF HUCK FINN combining live action and animation was later featured in the Banana Splits & Friends syndicated package of the 1970s.
The series featured Kevin Schultz (one half of an acting twin brother duo) as Tom Sawyer, Lu Ann Haslam (this was pretty much her only role) as Becky Thatcher, and Michael Shea as Huck Finn (he has been on the LAPD for decades).
This intro featuring Ted "Lurch" Cassidy as Injun Joe was originally shown at the beginning of each episode. It cleverly explained that the trio was chased by escaped murderer Injun Joe who vowed to follow them anywhere they went -- even in cartoonland where they ended up with Injun Joe (or his animated doppelganger) as the weekly villain. Hanna-Barbera Productions gave viewers 20 entertaining episodes with many directed by Hollingsworth Morse - director of F-Troop, H.R. Pufnstuf and many other 60s & 70s classics.
I loved watching this filmed series - heavy on the 60s blue-screen and optical printer effects. It looked so fun to comfortably run around barefoot in exotic locations such as Egyptian desert, Aztec jungles, and (in one episode) inside a whale's belly.