A Space Monster is Born on Earth (地球生まれの宇宙怪獣 Chikyū Umare no Uchū Kaijū) is the 27th episode of Ultraman Cosmos.
One day, something fell of from space and crash landed on Earth. EYES were sent to investigate and decided to get the monster out from the crater. Failed, Musashi summons Cosmos and successfully rescued the monster but it get away easily. Cosmos tried to stop it but to no avail hit by the monster's belly. EYES stopped Cosmos revealing the monster is pregnant as he uses Full Moon Rect to make it asleep for a while.
Back at EYES base, Ikiyama appeared and reveal the monster's name Zaranga, having come to Earth and later to the ocean numerous times even during the Edo period in order to give birth to her child. If she failed, her body temperature will rise to the temperature of a sun and even her died of heat stroke. Team EYES dispatched in order to change Zaranga's route to sea in order to avoid the city. Ikiyama revealed that Zaranga was supposed to crash landed on sea but it hit the mountains instead due to firework celebrations as it hates the smell of gunpowders.
As Zaranga follow the Sheepherd (Team EYES' patrol car), the sun's heat accelerated it's temperature and Team EYES needed to be quick as they even launched ice bombs to cool her down but the car stopped by some tourists whom seems to fond on Zaranga. They even release some fireworks making it superheated and went on a rampage. Musashi transformed into Cosmos and cool her with Luna Cold while using the Transformer Bubble to drag her to the sea so she can finally give birth to her baby. She succeeded and fly back to space along with her baby, where everyone watched the two mother and child flying away happily.
- Musashi Haruno (春野ムサシ Haruno Musashi): Taiyo Sugiura (杉浦 太陽 Sugiura Taiyō)
- Captain Harumitsu Hiura (ヒウラ ハルミツ 隊長 Hiura Harumitsu Taichō): Daisuke Shima (嶋 大輔 Shima Daisuke)
- Shinobu Mizuki (ミズキ シノブ Shinobu Mizuki): Kaori Sakagami (坂上 香織 Sakagami Kaori)
- Keisuke Fubukiフブキ ケイスケ (Fubuki Keisuke ): Hidekazu Ichinose (市瀬 秀和 Ichinose Hidekazu)
- Koji Doigaki (ドイガキ コウジ Doigaki Koji): Koichi Sudo (須藤公一 Sudō Kōichi)
- Ayano Morimoto (モリモト アヤノ Morimoto Ayano): Mayuka Suzuki (鈴木繭菓 Suzuki Mayuka)
- Ultraman Cosmos (ウルトラマンコスモス Urutoraman Kosumosu (Voice) : Hiroyuki Sato (佐藤浩之 Satō Hiroyuki)
- Ultraman Cosmos
- Luna Mode
Ultraman Cosmos Volume 6 features episodes 25-28.