 Japanese title card · “The True Form of the Metarex!?” | |
| Series | Sonic X (ソニックX), TMS Entertainment |
| Season | Season 3 (2005–2006) |
| Episode | Season 3, episode 20 · no. 72 of 78 |
| English title | “Zelkova Strikes Back” (4Kids) |
| Japanese title | メタレックスの正体！？ (Metarekkusu no Shōtai!?, “The True Form of the Metarex!?”) |
| Japan | Not shown on Japanese TV until 22 April 2020 (Kids Station) |
| First aired (US) | 18 March 2006 · 4Kids TV (Fox) |
| Directed by | Mitsutaka Noshitani |
| Written by | Kiyoko Yoshimura |
| Storyboard | Seiji Okuda |
| Previous episode | Hedgehog Hunt (S03E19) |
| Next episode | The Cosmo Conspiracy (S03E21) |
Metarex SagaYellow Zelkova
Zelkova Strikes Back is episode 20 of Season 3 of Sonic X and the 72nd of the anime’s 78 episodes. In Japan it is called “The True Form of the Metarex!?” (メタレックスの正体！？). It premiered in English: 4Kids aired it on 4Kids TV (Fox) on 18 March 2006, after a French TV debut on 12 April 2005, while Japanese TV only showed it on 22 April 2020. It was directed by Mitsutaka Noshitani and written by Kiyoko Yoshimura.
Synopsis
Back on the move after their stay at the café, the crew shakes off a wave of Metarex fighters, only for the Blue Typhoon to be struck by something its radar cannot see: Yellow Zelkova, clinging to the hull. He is out for revenge, and his new energy shield, built by Eggman, turns aside everything the heroes throw at him.
The ship crash-lands on a molten planet – Thunderbolt, in Wikipedia’s account – and in the battle Chris and Sonic are thrown far from the others. Sonic and Knuckles go after Zelkova together, but the shield holds as the giant starts punching the Typhoon towards a lake of lava.
After Zelkova’s riddle, Knuckles takes him on head-first and wrecks his knee, and the crew runs a cable from the ship to channel lightning into the shield until it overloads. Stripped of his armour, Zelkova is knocked into the lava. Pale Bayleaf gleefully mocks Eggman’s failed shield, while Shadow and Rouge find a fake Emerald atop a tree – and the traitor Leon, dying inside it, who hands Shadow a memory chip.
Key Moments
- Yellow Zelkova’s Eggman-built shield.
- The Blue Typhoon crash-lands on a molten planet.
- Zelkova’s end in the lava.
Trivia
- Wikipedia’s character list says Knuckles tried to save Zelkova from the lava; Sonic Wiki Zone says that moment is in the Japanese version only.
- On home video: the So Long, Sonic DVD set (2007); and Discotek’s Sonic X Collection 2 (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 3 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.