They came across Jenny when they tried to defeat Tadpolezilla in the episode Teen Team Time. After Misty found out it's weakness was spanking, Jenny helped them defeat it before learning about them and temporarily becoming a member. However, when Tadpolezilla matured into Toadzilla and attacked the Goop Zone, Jenny wanted to defeat it even though the other members wanted to leave. After Jenny tried to defeat it, Misty came and helped her before Brad caught it's attention by a spotlight. Toadzilla tried to attack Brad by its tongue, however the tongue hit the spotlight and got electrocuted. Misty, Squish, and Orion then left to go back to the stars.
At some point after their debut, the Teen Team broke up (mainly due to Orion wanting to join the ballet). While it is unknown what happened to Orion and Squish, Misty later went on to appear in two additional episodes.
Misty and Squish's names involve their powers: Misty turns into mist and Squish squishes into something.
Orion, on the other hand, is probably named for where he might come from: possibly somewhere in the Orion constellation, the Orion Nebula, or the Orion Arm.