This actually happened. Colin Baker, in character as Six, introduced the broadcast of Trial of a Time Lord #4 at the tail-end of a Saturday evening puppet show called Roland Rat - the Series. That, my dad tells me, is probably either Kevin the Gerbil or Reggie the Rat dismissing Doctor Who as rubbish and dodging a laser.
Roland Rat - the Series - 27th September, 1986
#The Cat Who Walks by Himself