— Logan in reply to Harmony asking why they should help Lucky, Lucky's Quest
Logan the Cat, formerly known as Log, is a character who makes his debut in Lucky's Quest as a SlugTerra-born loner alongside his sister Lizzie(formerly Blizzard) looking for their uncle(revealed to be Longmire). He is a domestic cat(breed unknown, possibly American or Domestic Shorthair), and his design is based off of the scrapped character Thunder(not to be confused with the Umbreon or pale brown and white tabby cat of the same name from The Legend of Fox the Brave)
Logan is a tomcat with thick dark brown tabby fur and and amber eyes. Unlike the character his design is based off of, Logan does not have any apparel.
Logan is a bit of a showoff, as he loves to climb trees to show off his skills, even if he gets stuck sometimes. Despite this, Logan appears to inherited his uncle's warrior-like nature, in that he is loyal to his friends, and is willing to risk his life for them. Even when Finitevus tricks Logan, Harmony, and Lizzie into leaving Lucky, Logan is still loyal to him enough to convince an angry Harmony to help the pup when he's pursued by Scourge.
Logan was born as Log, and his sister was Blizzard, and they were raised by their mother, revealed to be Longmire's sister Willow(who he was separated from when their parents were murdered when he and Willow were kits). Log and Blizzard were told of Longmire during their kithood, and after their mother passed away, Log and Blizzard moved to Mobius to find their uncle, meeting Lucky and Harmony along the way. Log is renamed Logan by Lucky, while Harmony commented that "Log" and "Blizzard" sounded like dire wolf names. Logan shrugs and says that they were their names, and they never questioned it. When Lucky finds Finitevus, the mad doctor convinces the coyote's companions to leave, leading to them feeling betrayed and hurt. Later, when Lucky is being pursued by Scourge after discovering Finitevus' true intentions for him, Logan convinces an angry Harmony to help the pup, though they are too late, and Lucky is kidnapped. Logan, Lizzie, and Harmony find and contact the warriors to tell them of Lucky's kidnapping, and help rescue him. Afterward, Logan and Lizzie meet Longmire, and become Storm Fighters, learning how to become warriors from him.
Logan loves to climb trees, and uses this skill to scout out routes for his friends. Austin mentions this to be a useful skill for warriors when he accepts Logan as a warrior.
Lizzie is Logan's sister, and he cares deeply for her, especially after hearing how their mother and uncle were separated as kits.
Harmony is a good friend of Logan, and Lucky suspected she liked him because she found someone she could argue with.
Lucky is a good friend of Logan, and though the cat felt betrayed by Lucky when Finitevus convinced him to leave after the pup found him, Logan still chose to save Lucky when the coyote was pursued by Scourge.