The episode begins in the Krusty Krab where a man gets a Krabby Patty, but then a baby comes and takes the patty. Everyone thought it was cute, thinking it was a real baby, but Mr. Krabs was able to see Plankton inside the baby. Mr. Krabs started beating him up, but because everybody still thought it was a real baby, they were all outraged. Then Mr. Krabs ripped off the head revealing Plankton inside a baby robot. Mr. Krabs put the head back on and launched him back to the Chum Bucket, and Karen then took off the diaper and puts it in the trash where Plankton walks out. Karen told him that he should get a pet and SpongeBob, who just happened to hear their conversation, decided to help him look for a pet. At the animal shelter, Plankton sees a guard worm, an old gross snail, and even Patrick. Plankton almost gets swallowed by a pet, but then an amoeba saves his life. Plankton chooses the amoeba as his pet and decides to call him Spot. At the Chum Bucket, Plankton teaches Spot some tricks like stay, sit, and roll over. Then he teaches him how to steal a Krabby Patty. Plankton wasn't finished talking when Spot left to the Krusty Krab unseen to get a Krabby Patty. When Spot comes back, Plankton is rapt, thinking he finally won but is then enraged when Spot eats the Krabby Patty in one bite. He punishes Spot by tying his leash to the mailbox. Seconds later, Plankton feels bad, but when he runs back outside he finds Spot's leash, with no amoeba to be seen. Plankton then goes out to find him, with SpongeBob's help. Soon, they stumble upon the shelter, then go inside. It is very dark inside so SpongeBob tries to find the light switch. There are 2 switches, so SpongeBob turns on both. One turns on the lights, and the other opened the pens. The guard worm, sea monkey, and sea urchin all chase SpongeBob and Plankton. When they lose the animals, Plankton realizes Spot had been on his optical cornea (his eye) the whole time. The other pets then find Plankton and SpongeBob again so Spot tries to scare them off. The animals laugh at Spot because he's so small but then he grows about a hundred times bigger and easily scares the animals away. Plankton then decides he is going to keep Spot and was sorry he yelled at him.
As of September 26, 2017, The Internet Movie Database (IMDB) gives this episode a rating of 8.5/10 based on 116 ratings by users. TV.com users give this episode a rating of 9.2/10 based on 16 votes.
In the title card, a picture of an amoeba can be seen, which implies the appearance of Spot in the episode.
This episode was paired with "Gary in Love" when it premiered.
Running Gag: Fish saying "Awww!" to Plankton.
SpongeBob mentions that he got Gary from the animal shelter. This is true, because in "Treats!," Gary showed SpongeBob a baby picture of him, and SpongeBob claims it was when he got him from the pound.
Plankton breaks the fourth wall in this episode by saying "Holy plot twist!" when Spot gets the Krabby Patty. However, in Russian version, he says "Oh my Neptune!". It is unknown why it was done.
When Plankton takes Spot for a walk, he tires over walking a long distance in comparison to his height. Yet, when he ties him to the mailbox post, he does not tire from the walk to and from said mailbox post. In fact, he even makes both the trips in record time for his size.
When Spot multiplies into a large organism, this is through a process of cellular division known as mitosis, where a cell makes a replication or clone of itself.
When SpongeBob says Gary lost him, he might have been referencing the events of "Have You Seen This Snail?"
However, this is unlikely, as he then says that it was the worst eight minutes of his life, and in that episode, Gary was most definitely lost longer than that.
The amoeba on the title card looks similar to the old Nickelodeon logo.
In the Hebrew version of this episode, there were no words on the title card.
This episode takes place before or after "Grooming Gary" because Mrs. Squiggles is at the animal shelter. If it is before then her owner got her after Plankton got Spot or said owner released her to them.
In the pound, Patrick is in one of the cages. Ironically enough, this was the same year he was nominated for Best Animal Sidekick in the 2014 Kids' Choice Awards and he won.
There's an episode of Phineas and Ferb called "Spa Day" that is outwardly similar to this one. In the aforementioned episode, the People of Danville say "Awww!," which made Doofensmirtz ask "Don't you people have jobs?," similar to how the people of Bikini Bottom saying "Awww!" and Plankton saying the same thing in response.
When SpongeBob flips the switch that opens the animal pens, the sea urchin was in the third pen and the guard worm was in the second pen. Later, when Spot scares the animals back into their pens, the sea urchin goes into the second pen and the guard worm goes into the third pen. It's possible that the sea urchin and guard worm were too scared to remember what exact pens they were in.
When Spot is in the Krusty Krab and SpongeBob opens the kitchen door, for some reason, SpongeBob's mouth is moving but no dialogue is heard.
Right as Plankton (who was still in his baby disguise) was about to land in front of the Chum Bucket after being kicked out of the Krusty Krab by Mr. Krabs, the road that usually connects to the Krusty Krab isn't there.
In Israel, the episode's name is not shown.
This occurs in numerous Season 9 episodes in that country.