Space Dolphins are a species of space faring mammals that resemble the Earth based family Delphinidae, better known as Dolphins. The Space Dolphins have became particularly associated with intergalactic bounty hunter Lobo. The Space Dolphins are perhaps the only thing that Lobo will not harm in any form, and, in fact, will actively seek to better their being.
The Green Lantern planet Mogo was once besieged by a shower of corrosive yellow matter. Since his ring was powerless to stop the matter, he created a holographic agent to barter away the matter to the star traveling salesman Manga Khan, who traded two canisters of the matter, in an inert state, for two Space Dolphins caught by Manga's Cluster. Unknown to Manga Khan, however, the intergalactic bounty hunter Lobo, a self proclaimed protector of the dolphins, was after the person who had captured the Space Dolphins.
Luckily for Manga Khan, the New God Mister Miracle was near to suggest they track down the person who had bought the dolphins. When Lobo and Miracle approached the planet where the person who had bought them resided, the planet itself began attacking them. The holographic agent that had purchased the dolphins approached the two and explained to them that the dolphins would be safer on the planet than elsewhere. Lobo begrudgingly agreed. Neither he nor Miracle found out that the planet itself had been the being to contact them. It was also revealed that Mogo had needed the dolphins since they eat the corrosive material and need it as part of their diet.
Aquaman also had an encounter with the space faring cetaceans, during which it was revealed that on occasion, they had came to Earth and interbred with the local species. One space dolphin even befriended Aquaman's adopted mother, the Bottle-nosed Dolphin Porm.
Since then, the Space Dolphins have become associated greatly with Lobo, even with few appearances. One notable storyline involving them was during 52, when Lobo was the "space pope" of an interstellar religion called the Church of the Triple-Fish God, that was headed by a Space Dolphin god. Lobo also had a personal attendant nicknamed Fishy, who acted as a reminder of the vows Lobo had taken. Lobo ultimately was able to escape from his vows by killing the Triple Fish-God with the Emerald Eye of Ekron.