Originally Posted by Paranoid Randroid
But Mort Walker isn't dead, and neither Peanuts nor BC were continued after their authors' expiration.
BC is, in fact, still going. Done by Hart's grandsons, Mick and Mason Mastroianni. (Mick also writes Wizard of Id, which is drawn by Brant Parker's son.) Much the same situation as Hagar (done by Dik Browne's son, Chris) and Blondie (by Chic Young's son, Dean).
Tatulli has confirmed it's Hi.
(You'll need to scroll down a whole lot - can't link straight to the comment.) Strange how many posters there think Hi's either Heart or Dean, from Tatulli's other strip, Heart of the City....