The Domino Effect

"The Domino Effect" is the first segment of the fourth episode of the first season of Amphibia, and the seventh episode overall.

It premiered on June 20, 2019 alongside "Taking Charge".

Synopsis
Anne wants to keep a caterpillar as a pet, but she'll have to keep it a secret from Hop Pop.

Plot
The episode starts with Anne and Sprig playing "baseball" outside, using a heavy watermelon and a scythe. Sprig carries the watermelon and aims it at Anne. However, Anne overswings the scythe and swings it at Sprig's hat instead of the watermelon. As a result, Sprig's hat splits up in half and reveals that he has orange hair. Just as Anne is about to retrieve the scythe, they suddenly hear a sound, and follow it to a trio of giant wasps attacking a small creature trapped in the mud. After rescuing it, Anne discovers that the creature is a small caterpillar that resembles a cat, specifically Anne's cat Domino from back home. Anne immediately falls in love with the creature despite Sprig's reluctance to take it in, due to Hop Pop's strong stance and dislike against keeping pets. However, Anne wins him over with a lick from the caterpillar, dubbing the caterpillar Domino 2. Anne asks Hop Pop directly about taking a pet in, but he instead angrily goes off on how Sprig and Polly once had a pet tarantula named Charlie Bigbottom who always caused a mess. While still uncomfortable with Domino 2, who has begun licking and "play biting" him, Sprig distracts Hop Pop with the stories of Charlie Bigbottom while Anne sneaks the cat-like creature into the basement.

The next morning, Sprig goes down to Anne's room is covered in cobwebs. After searching for Anne, he notices that she is covered in scratch marks from Domino 2, but she insists that she is just getting used to this new environment. The caterpillar frighteningly glares at Sprig and spits a cobweb at him, which Anne believes that means "I love you" and kisses her. After spending a day hiding Domino 2 from Hop Pop and Polly while she showed interest in eating Polly, Domino 2 takes a nap in the basement as Sprig and Anne leave to get some food. Unknowingly, Domino 2 begins to cover herself in a cocoon and begins to grow. Anne and Sprig start eating upstairs when Hop Pop catches them and demands to know what they had been doing all day. After hearing a noise, the three rush downstairs to find that Domino 2 is missing. Anne accidentally calls out her pet's name and Hop Pop figures it out. Sprig mentions that it was black with white spots and Hop Pop claims that they had taken in a coastal Kill-a-pillar just as she drops from the ceiling in front of them, already having transformed into a deadly cat-like butterfly. As the three try not to make a sound and tiptoe out of the basement, Polly bursts in that moment to see what was going on, causing Domino 2 to react ferociously and beat her wings as she rushes after the Plantars.

Despite Anne's efforts in keeping Domino 2 at bay, she begins attacking the Plantars forcing Anne to lead her outside with one of her mouse toys. After getting far away, Anne solemnly tosses the mouse toy into the wild as Domino 2 rushes after it as Anne watches her sadly. Upon coming back, Anne apologizes and Hop Pop initially furious, breaks down into tears, admitting that he misses Charlie Bigbottom. The next day Anne is cleaning up the basement while Sprig tells her that it is not difficult to take in a wild beast and keep it as a pet (referring to her) and offers an ugly stuffed doll version of Domino II to her which she lovingly hugs.

Cast

 * Brenda Song as Anne Boonchuy
 * Justin Felbinger as Sprig Plantar
 * Bill Farmer as Hop Pop Plantar
 * Amanda Leighton as Polly Plantar

Pictured

 * Domino

Other characters

 * Domino 2

Trivia

 * This episode premiered on the same day as the Season 4 premiere of the Disney Channel sitcom BUNK'D.
 * Anne's cat Domino was named and inspired after Matt Braly's real-life cat, also named Domino.
 * This is the first episode where Sprig is seen without his hat.

Revelations and significant events

 * Sprig is revealed to have orange hair, as well as dark spots on the side of his face like all the other frogs.
 * The Plantars used to have a pet spider named 'Charlie Bigbottom'.
 * Hop Pop has a dislike against keeping pets because he had to do all the chores of caring for a pet.

Continuity

 * Sprig's slingshot skills are seen again when he is fighting off the bees.
 * Sprig's short attention span and that he is easily distracted is shown again when Anne tries to lure Domino 2 to follow her.
 * The giant pile of dishes alludes to "Cane Crazy", where Anne was placed on dish duty for breaking Hop Pop's cane; it's shown here that she seems to put off actually doing it.

Allusions

 * "The Domino Effect" - The title is a real-life theory that states that a small event in one place can lead to a chain reaction of events that could prove to be disastrous.

Errors

 * After the scythe blade destroys Sprig's hat, he is seen without it, but when it cuts to the next scene, he is seen with his hat even though it was destroyed.
 * When Hop-Pop catches Anne and Sprig eating, Sprig eats a lot of tomatoes. In the earlier episode "Hop Luck", it was mentioned that no farmer grows tomatoes and that they are very rare because they come from a dangerous plant. The tomatoes were also bigger than the ones appearing in this episode.
 * When Hop-Pop is questioning Sprig, he is seen sweating. Earlier in "Flood, Sweat & Tears", he claimed that frogs don't sweat.
 * When Sprig, Polly and Hop-Pop are under attack from the Kill-a-pillar, they are under the claws of the beast and the Kill-a-Pillar lets them go to follow Anne. When Anne returns home, Sprig is tied up in cobwebs and Hop-Pop is seen removing cobwebs from Polly, while self-covered in left-over cobwebs. When they face Anne after she walks in, Sprig is suddenly free and all the cobwebs are gone. They never got caught in cobwebs when the Kill-a-pillar chased them.
 * While Anne is about to toss the toy mouse, when she is talking to Domino II, her torso cuts off at the bottom of the screen.
 * When she does throw it, it disappears right as she throws it away.
 * The basement floor door is square when Anne about to and does go into the basement, but throughout the episode, it's shown to be a regular door (like other episodes).
 * Ironically, the door is nowhere to be seen when the scenes of the kitchen are shown.
 * When Anne goes to say sorry to the Plantars, the door is seen but turned 90° clockwise.
 * When Anne cleans the basement, her backpack is seen in the background. However, it is missing a lot it its stickers.
 * When Sprig gives Anne a plush of Domino 2 (made from its hairballs), the left eye lowers, but in the very next scene, it's somehow fixed.

Edits

 * In the Southeast Asia broadcast, "I swear to the frog" was cut. Anne's line "Welcome, brother, to the church of cute" was shortened to "Welcome, brother". Then Sprig's line "This a cult thing?" was cut. Also the line "What the heck is that?" was shortened to "What is that?" Anne saying "Oh, crud." was also cut.