Seeratter existed within the Outer Rim Territories of the galaxy. The Villarandi Kradon Minst brought the Gloovan Twinkle Sisters to the attention of Jedi Matthea Cathley and Vildar Mac in the Enlightenment tapbar of Jedha (a moon located in the Mid Rim), around 382 BBY, describing them as "the best bouncers this side of Seeratter."
Maz Kanata, the infamous pirate queen, concealed some of her ill-gotten gains from her time as a pirate on Seeratter, storing them in a subterranean vault protected by an antitamper sub-space alarm. When she noted Seeratter on a map within the Smuggler's Guide logbook sometime before or during 10 BBY, the alarm safeguarding the hidden treasure on Seeratter was still inactive.
The planet Seeratter was initially referenced in Star Wars: Smuggler's Guide, a sourcebook penned by Daniel Wallace which was published in 2018.