Lio into the strip itself (see Lio and the Fourth Wall). And Crockett Johnson's classic children's book character Harold did the same thing.
In his adventures with his purple crayon, 2-dimensional lines were continually reinterpreted, driving the story forward. They sometimes came to life, and sometimes made pictures that become the objects they depicted.
Except in this sequence. (click to enlarge).
Johnson was also a comic strip creator. His innovative work Barnaby ran from 1942-1952. Which makes this a nice tribute from one comic strip artist to another.