Back in the heady days of the Clinton/Lewinsky scandal John Goodman hosted SNL for the umpteen jillionth time and at the 56 minute mark of this clip you can see a dumb sketch whose concept predates Snakes on A Plane by eight years. The sketch is retarded, but at the end of it, after the plane crashes (using footage stolen from Die Hard 2) a snake puppet appears in front of the camera with a woman's voice and gives a creepy minute-long childlike monologue to the audience about playing games with "meeeee!" What the snake says is just so bizarre I thought SNL writers were snorting coke when they wrote it, or hired one of their six year old kids to write it.
This is also from presumably the late 90s and is one of those "Saturday TV Funhouse" bits done by Robert Smigel. It isn't very funny--it's an episode of Friends, but with the apocalypse happening in the background, and the joke is that the characters are so self-absorbed that they don't realize what's happening, but shortly after the "apocalypse" starts, in the upper left hand corner of the screen you see the New Years' ball being lowered for the year 2000, and instead of a ball, it's Dick Clark's head, which explodes into a blast of blood and eyeballs when it touches the ground. For whatever reason (ever since Raiders Of The Lost Ark I've had a fixation on exploding heads) I've never forgotten that.
Is Jam! the British sketch comedy series that had a commercial break announced by a swinging skeleton puppet that said something like "I'm Ian Curtis and we'll be right back!" Because I know I've seen that.