S.O.S. Mount Fuji (SOS富士山 Esu Ō Esu Fujisan) is the seventh episode of Ultra Q.
When Yuriko investigates increased volcanic activity in the Mt. Fuji area, she learns the story of a modern-day Tarzan named Takeru, who is rumored to live in the region's dense woods since becoming lost within them 15 years ago. Meanwhile underground volcanic energy creates boiling temperatures in a lake at the foot of the mountain and a huge boulder erupts from the waters. Because the rock obstructs a main travel route, it is blasted apart with dynamite and the pieces are transported back into the forest. At one night, the pieces collect around a strange luminescent rock, creating an enormous rock monster called Gorgos that lives and breathes like an animal. While the investigative trio searches for Takeru with the help of his older sister Mitsuko, an area policeman finds him trapped by the monster beneath a fallen tree and helps him to escape. Takeru rushes the others to safety and then confronts the monster alone. Climbing on the creature's back, he is successful in destroying the mysterious glowing orb which functions as the monster's heart and the beast falls over dead. Takeru is reunited with his sister and happily returns to civilization.
- Jun Manjome (万城目淳 Manjome Jun): Kenji Sahara (佐原 健二 Sahara Kenji)
- Yuriko Edogawa (江戸川由利子 Edogawa Yuriko): Hiroko Sakurai (桜井 浩子 Sakurai Hiroko)
- Ippei Togawa (戸川一平 Togawa Ippei): Yasuhiko Saijo (西條 康彦 Saijo Yasuhiko)（credited as "西条康彦”）
- Narrator (ナレーター Nareta): Koji Ishizaka (石坂 浩二 Ishizaka Koji)
- Police officer Yokoyama (横山巡査 Yokoyama Junsa): Dai Kanai (金井 大 Kanai Dai)
- Technical officer Hayakawa (早川技官 Hayakawa Gikan): Jun Hongo (本郷 淳 Hongo Jun)
- Takeru (タケル Takeru): Eishiro Takashima (高嶋 英志郎 Takashima Eishiro)
- Mitsuko (光子 Mitsuko): Kazuko Ichikawa (市川 和子 Ichikawa Kazuko)
- Jiro (次郎 Jiro): Tadashi Hanabusa (花房 正 Hanabusa Tadashi)
- Kinta (金太 Kinta): Jiro Yamazaki (山崎 二郎 Yamazaki Jiro)
- Sonoko (ソノ子 Sonoko): Satomi Tachibana (立花 里美 Tachibana Satomi)
- Rock processing worker A (岩石処理作業員A Gansekishorisagyoin Ei): Haruno tic (晴乃 チック Haruno chiccu)
- Rock processing worker B (岩石処理作業員B Gansekishorisagyoin Bi): Haruno tac (晴乃 タック Haruno Takku)
- beard man (ヒゲ Hige): Hideyuki Aoki (青木 英行 Aoki Hideyuki)（Noncredit）
- Surume (スルメ Surume): Hideyuki Yamaguchi (山口 秀幸 Yamaguchi Hideyuki)（Noncredit）
- Announcer (アナウンサー Anaunsa): Hisashi Saeki (佐伯 久 Saeki Hisashi)（Noncredit）
- Ultra Q Volume 2 features episodes 5-8, & Total Natural Color Blu-Ray Volume 2 Features Episodes 4-7.