SpongeGar is likely to be more advanced than the Primitive Sponge because he has developed clothes, a language system, domestication, and a curiosity for new discoveries, such as cooking food.
His pet snail, Prehistoric Gary, was a lot larger than the present Gary raised by the normal SpongeBob. This Prehistoric Gary was most likely an ancestor of the normal Gary.
His best friend is Patar, who is one of Patrick's prehistoric ancestors. He is not the same as Primitive Sponge; he came many years after the primitive. He is curious and smarter than Primitive Sponge. SpongeGar is also an ancestor of SpongeTron.
Like his descendant, SpongeGar is a sea sponge, but he is drawn to resemble a kitchen sponge. SpongeGar has large light blue eyes, a long, slightly curved nose, a large mouth with one buck tooth, two fang-like teeth, a unibrow, and dimples with three freckles on each cheek. He wears a brown animal skin with only a left sleeve (he also uses it as a blanket to sleep with). He also has hair showing from his feet and hands.
He was mistaken by Squog (the prehistoric version of Squidward) to be dumb, but he has proven to be somewhat intelligent.
His personality is similar to that of Primitive Sponge but they are not the same, as SpongeGar is more advanced and curious than the Primitive. At times, he can be like SpongeBob, as after he, Squog, and Patar argue over the fire before it is washed away, he and Patar are both saddened about it even more so as they realized what they had been doing hugging to make up.
He lives in a pineapple-styled cave with his prehistoric pet snail, Prehistoric Gary. His neighbors here are Patar and Squog. At one point of the episode, they all fight over a fire, but the fire goes out.
Like his descendant, SpongeBob, he lives in a structure that lies near his nears as if it were a straight line. Unlike a real pineapple, the house was a simple stone house that serves as shelter like a cavern. However, the house was able to stretch easily when huge Prehistoric Gary came out.
During the caveman times, to wake him up, SpongeGar relied on creatures whose roars make a powerful enough vibration to knock a rock off a shelf and onto himself as an alarm system. Specifically, a Dorudon.