 Japanese title card · “The Ghost of King Boom Boo in the Old Castle” | |
| Series | Sonic X (ソニックX), TMS Entertainment |
| Season | Season 1 (2003–2004) |
| Episode | Season 1, episode 19 · no. 19 of 78 |
| English title | “Sonic’s Scream Test” (4Kids) |
| Japanese title | 古城の亡霊キングブーブ (Kojō no Bōrei Kingu Būbu, “The Ghost of King Boom Boo in the Old Castle”) |
| First aired (Japan) | 10 August 2003 · TV Tokyo |
| First aired (US) | 7 February 2004 · Fox Box (Fox) |
| Directed by | Keiko Oyamada & Sim Sang-il |
| Written by | Hiro Masaki |
| Storyboard | Toshihiko Masuda |
| Previous episode | The Dam Scam (S01E18) |
| Next episode | Cruise Blues (S01E20) |
Ghost storyKing Boom Boo
Sonic’s Scream Test is episode 19 of Season 1 of Sonic X and the 19th of the anime’s 78 episodes. In Japan it is called “The Ghost of King Boom Boo in the Old Castle” (古城の亡霊キングブーブ). It premiered on TV Tokyo on 10 August 2003, and the 4Kids English version followed on Fox Box (Fox) on 7 February 2004. It was directed by Keiko Oyamada & Sim Sang-il and written by Hiro Masaki.
Synopsis
Lindsey is shooting a film in an old castle on a lake, and the whole gang comes to watch. Ella has a part as a maid, Lindsey takes Tails for a boy in a fox costume, and Cream and Cheese keep wandering into shot. Then a cameraman knocks an hourglass-shaped talisman off its pedestal, and the castle wakes up.
Ghostly hands snatch cast and crew one by one, Sonic included, until only Chris and Amy are left. Beneath the pedestal they find a passage down to the ghosts’ lair, ruled by King Boom Boo, who mimics Sonic’s voice to trick Amy into setting the talisman in place – which only makes him stronger.
Chris thinks fast and turns the hourglass over, freeing the prisoners and letting Sonic and Amy drive the ghosts back. Outside, the heroes seal the chamber again, though Chris puts the talisman back the wrong way up, and a police officer tells them that nobody has ever escaped the castle’s ghosts before. Up in a window, two of them are still laughing.
Key Moments
- King Boom Boo, a boss from Sonic Adventure 2, haunts the castle.
- Lindsey Thorndyke’s film shoot takes the gang to a haunted castle.
- Chris saves the day by flipping the hourglass talisman.
Trivia
- King Boom Boo comes from Sonic Adventure 2 (2001), where he is one of the bosses Knuckles faces.
- On home video: Japanese DVD/VHS volume 5 (Victor Entertainment, 21 November 2003); 4Kids/FUNimation volume 5, Sonic’s Scream Test (25 January 2005); the Chaos Emerald Chaos DVD set (2008); and Discotek’s Sonic X Collection 1 (2016) and complete-series Blu-rays.
Watch the Episode
The full 4Kids English episode, uploaded by TMS Entertainment’s official “Anime! on TMS” YouTube channel (checked 6 November 2026).
Part of our Sonic X Season 1 guide. See the Sonic X series page for the cast, theme songs and home video.
Sources: titles, credits and air dates from Wikipedia’s list of Sonic X episodes and Sonic Wiki Zone, cross-checked with each other and with Luke’s original Sonic Scene episode table; synopsis written for Sonic Scene from the episode, Wikipedia’s summary and Sonic Wiki Zone’s plot notes; title card and screenshots via Sonic Wiki Zone, copied to our media library.