Calvin and Hobbes by Bill Watterson for April 09, 1990
Hobbes: There goes Rosalyn around the house again. She still doesn't know you sneaked back insdie. Calvin: Now I'll change back into my secret identity alter ego! Hobbes: Uh oh. She saw the light on in this room. She's coming in! Calvin: Quick! Get in the covers! Pretend we've just been reading in bed! Hobbes: But she knows you attacked her and ran outside half an hour ago! Calvin: That was Stupendous Man. Not mild-mannered Calvin! I've been in bed with my PJs on since 8:00. Hobbes: You think she's going to believe that? Calvin: My covers are here. My pajamas are here. It's as plain as can be!