Do you mean like this? 
I don’t think anyone’s mentioned one of my favorites yet.
Scene: a science lab, full of equipment and complex equations on the blackboard. The dignifed, white-coated scientists…are rushing out the door shouting in delight at the sound of the ice cream truck.
Two spiders, one wearing a mask, the other with bugged out eyes and a pile of spider silk under his butt. Caption: “Whoa, Bob, did I scare ya?”
Lady posting a “lost dog” sign on the bulletin board with a small dog stuck in her butt.
Polar bear munching on an igloo.
“Yum, crunchy on the outside, chewy on the inside.”
I’m way over 40, but I have no idea what this one means.
Laboratory Peer Pressure
Three disfigured lab techs offering a test tube of chemicals with smoke rising from it to a normal looking lab tech
“Hey, look what Zog do!”
A group of cavemen around a campfire, holding animals in the flames to cook them, in obvious pain, in the background sits a nerdy looking caveman sitting at a smaller campfire cooking an animal…
…he has the animal on a stick, and he’s holding the stick, cooking the animal without burning himself
“Early scientists describe the first “dirt” molecule”
“DE” and “Dert” on a whiteboard, some cavemen looking through their hands like they were binoculars at the dirt in front of them
My biology prof in college used this in one of his lectures.
I teach Taekwondo. This cartoon hangs in our school’s office.
Just the other day I was thinking about a great Far Side:
Science lab with a tank full of dolphins, microphones all over, scientist with earphones is saying “It’s another one of those aw-blah-ess-pan-yole sounds”. Another scientist is at a tally board where the following sounds are listed with varying tally frequencies:
aw-blah-ess-pan-yole
kay-passuh
bway-nohs-dee-ahs
etc.
I just re-read this thread and am shocked that I hadn’t posted my all-time favorite Far Side cartoon back in 2003:
Front yard. A winding, tangled path has been mowed through the yard. Man with his hands on hips is scolding the dog: “You call that mowin’ the lawn? Bad dog! No biscuit! No biscuit!”
(Whenever I make a boneheaded mistake, I yell to myself “No biscuit! No biscuit!”)
A hunter and his guide/assistant are standing in tall grass on the African Savannah. Several cape buffalo graze in the distance, but among them stands a mime. Hunter says “Situation’s changed Jules, put away my buffalo gun and get me my mime rifle.”
This is just what came to my mind when I saw the thread title! Feathers all over the place. And the usual (for Far Side) deadpan expression on kid God’s face.
Oh well, at least he didn’t have parents or sibs to witness the goof.
A cargo ship of mannequins is sinking in the background of an ocean scene, and some of the cargo is floating free in the water.
Two sharks have their heads out of the water and one seems to be coughing out bits of plastic. The caption reads:
“What is this…? A* Cruel Hoax!?*”
…its one of my favorite sayings to this very day… 
When this zombie popped back up in my CP, I was just about to repost this same cartoon. 10 yrs and still my fave
Sort of an indirect MAD memory, and of very recent vintage, but anyway…
I just picked up a Signet paperback edition of John Lennon’s In His Own Write/A Spaniard in the Works at the Strand, and all of the “you’ll also enjoy reading…” suggestions on the first verso page inside are MAD collections.
Scene: Mom snake sitting at the dinner table with her two young sons (she’s rocking the cat eye glasses):
“Mom! Randy spit poison on my rat again!”
Laid me right out!
For Mad Magazine, the one whose last two lines I will never forget was from the early '80s. The Colombian drug cartels were up and running, delivering cocaine as fast as they could manufacture the stuff. The United States had initiated the insipid War on Drugs (so tough!), and this comic nailed the Colombian response:
“If it’s coffee beans you want”, he says,
“go and talk to Juan Valdez.”
This is my single favorite cartoon strip of all time.