"The Sidekick" is the first episode in the Sonic Boom television series. It aired on 8 November 2014.
When Tails is injured in a battle with Doctor Eggman, Sonic holds auditions for a new sidekick to replace him.
- Sonic the Hedgehog (First appearance)
- Miles "Tails" Prower (First appearance)
- Knuckles the Echidna (First appearance)
- Amy Rose (First appearance)
- Dr. Eggman (First appearance)
- Burnbot (First appearance)
- Orbot (First appearance)
- Cubot (First appearance)
- Fastidious Beaver (First appearance)
The episode starts off with Sonic chasing Dr. Eggman in his Egg Mobile through some canyons. The pair enters a corkscrew-shaped mineshaft where Dr. Eggman summons Burnbot to destroy Sonic, but Sonic mocks the inconsistency of Burnbot's name as it does not actually use fire. Regardless, Sonic and Burnbot chase each other towards the bottom of the mineshaft. Tails then arrives in the Tornado, where he contacts Sonic over their communicators and they make a plan. As Sonic and Burnbot are about to clash in the shaft, Tails flies in and helps Sonic counterattack Burnbot, where Sonic swings into the robot with an EnerBeam launched by Tails, knocking it into a wall. However, Burnbot gets up and clips the Tornado's wing, causing Tails to fall. Sonic and Burnbot then face off again, but Sonic knocks a boulder loose which smashes the robot and he gets out of the shaft, only to see Tails crash. As Sonic runs over to the wreckage, Eggman decides to retreat, taking Burnbot with him. Sonic finds Tails unconscious and in bad shape, but alive, and he carries him back home, promising he will never let this happen to him again.
Back at Tails' house, Tails awakens to Sonic's joy. Tails is ready to get back in action, but Sonic, rather than saying as it is, tells Tails that he has gotten early retirement from his job as his sidekick. Tails however, is confused, so when Sonic is about to leave, he lets him know that he fired him, but Tails takes it casually. While feeling guilty about his decision, Sonic begins advertising for his "sidekick try-outs," where all qualified candidates are welcome, so Tails can stay in retirement. At Dr. Eggman's lair, Eggman, Orbot and Cubot learn about Sonic's try-outs. While Eggman finds this unbelievable (despite showing some interest in being Sonic's friends), it makes him slowly hatch an evil scheme.
At Sonic's house, the sidekick try-outs are at full swing with several participants having shown up. The first participant that tries out is Amy who tells Sonic that she wants to try out as his sidekick and starts juggling and singing, but Sonic is unimpressed. For the next, Fastidious Beaver appears, though he admits he is a coward. Sonic is then met by Amy once more who tries the tryouts again with the same act, except that she talks like an Italian pizza man, but Sonic sends her away. The next one up is Knuckles who wants to make Sonic his sidekick. While Sonic is apathetic about it, Knuckles goes on and states he would have to name him "Knuckles Jr."
At the end of the try-outs, a cloaked figure applies and Sonic is impressed by the guy's answers to his questions. However, the person then uncloaks himself (with some difficulty) and reveals himself to be Tails, who is attempting to become Sonic's sidekick again. Sonic disagrees, but Tails proves his right by bringing up that all qualified candidates can apply. Eggman then shows up to apply for the job too, but while Sonic is against it, Eggman uses the same argument as Tails. Despite the fact that Sonic is against them both becoming his sidekick, he begrudgingly lets them move on, and additionally accepts Fastidious Beaver as a third candidate and alternative when the latter wanted his parking ticket validated.
To test his candidates, Sonic sets up a race for them on Extreme Gear-like boards to Mount Safety to capture the red flag he has placed there. While Eggman gives Fastidious an early start, Tails and Eggman soon takes the lead where Eggman tries to use his board's weapons against Tails, but the latter manage to avoid them while knocking Fastidious out of the race. As Sonic watches the race, Tails and Eggman move onto the next part of it and fly towards the flag in the Tornado and Egg Mobile. However, Fastidious gives up and lies down in fetal position and sucks his thumb after his crash. As they fly towards the flag, Eggman reveals to Tails that his real plan with the try-outs is to get rid of both him and Sonic, and picks up Burnbot from the jungle.
Burnbot manages to clip the Tornado's wing again and Tails crashes in a frozen lake where he is stuck. However, Sonic comes to his aid and gets him out just before the Tornado sinks. There, Sonic comes clean and tells Tails he fired him to protect him. Eggman and Burnbot then face the duo again, except this time, the updated Burnbot can actually use fire, and uses it to make the ice they stand on crack. Sonic, unable to swim, falls through the cracks and into the water and Tails cannot get him out as he is water logged. Sonic insists to drown so Tails can get away, but Tails swims in and saves him. With Tails' help, Sonic lands a hard hit on Burnbot who cause the ice to crack further and it sinks into the lake. Sonic and Tails then flies away while Eggman retreats, promising to be back with a better robot.
As the sun sets, Sonic and Tails reconcile and Sonic basically rehires Tails as his sidekick. Back at Sonic's house, Amy demands a callback when Knuckles passes by and notes it was not going well with his own sidekick. Realizing Knuckles needs a sidekick, Amy starts her act again, and Knuckles gets another name idea for his sidekick: Knuckalina.
- This episode shows Sonic Hugging Tails for the first time.
- This episode was the first footage shown of the series back in February 2014.
- Like the first episode of Sonic X, This showed Sonic's weakness that he can't swim and saved by Tails. However, in Sonic X, he was saved by Chris Thorndyke.