The SpongeGar or Caveman Spongebob meme, technically known as Primitive Sponge, originated from the 1999 SpongeBob SquarePants episode 'SB-129,' where Squidward travels back in time. While often confused with SpongeGar, a character from the later episode 'Ugh,' this specific prehistoric Spongebob became a viral sensation on Reddit and Twitter in 2016. The image features a wide-eyed, hunched-over Spongebob with a primitive expression of alarm or confusion. It is typically used as a reaction image to describe sudden feelings of panic, social anxiety, or the primal instinct to flee when faced with an awkward or unexpected situation.