"The Volcanic Venture" is the forty-eighth episode of the anime series, Sonic X. It first aired on 29 February 2004 and 12 March 2005 in Japan and the United States respectively.
- "Gotta Go Fast" - Opening theme (USA and CAN)
- "Sonic X" - Opening theme (AUS, NZ and UK)
- "Gotta Go Fast" (shortened) - Closing theme
Traveling around on the island, Eggman plans to set off the hotspot with an explosion. While Sonic, Knuckles, and Rouge investigate the subterranean landscape of the island, the others are trying to locate Dr. Eggman. Unwittingly, the intruders awaken a giant Mogera-esque robot that attacks them. Over the course of a pitched battle, Decoe and Bocoe reject Dr. Eggman and try to help, but are sent flying. Sonic then throws Eggman's explosive into the robot, causing it to explode. The island begins to sink but everyone escapes. Decoe and Bocoe then emerge, having been rebuilt by Tails and Chuck and denounce Dr. Eggman.
- In the original version, the material Tanaka finds is called "Harashi mineral". In the English dub it is "Urmurashium".
- Some conversations between Sonic, Knuckles and Rouge are changed.
- In the original version, when Decoe and Bocoe do their imaginary transformation, they say nothing. In the English dub, a whole description was added.
- Right after Decoe and Bocoe's imaginary transformation, there is a shot of Mongroun with a thought bubble displaying a strong-looking robot, only for the thought bubble to pop and give him a red anger vein.
- In the Japanese version, Dr. Atsumi said he was kicked out of the university for suggesting the existence of Murashia.
- In the Japanese version, Decoe and Bocoe were destroyed when the island volcano erupted, and Tails and Chuck repaired them. In the English dub, this was changed to have Decoe and Bocoe say that they escaped from the island in time.
Title in other languages
|Japanese||ソニック対地底怪獣||Sonic VS the Monster from Underground|
|French||Le continent disparu||The lost continent|
|German||Die Vulkaninsel||The volcanic island|
|Italian||Avventura nel vulcano||Adventure in the volcano|
|Spanish||Sonic contra el monstruo subterráneo||Sonic against the underground monster|
- The title card resembles a "Godzilla vs." movie title.
- Mothmacin has a near resemblance to Mothra. Mongroun also bears a resemblance to Moguera.