Thurston is built far more broadly than the other zebras seen in the series, and has a much thicker neck. This is most likely meant to indicate his position as lead stallion of the herd. His muzzle is dark gray, almost black. He has a large tuft of fur atop his head that curls back and brown eyes with short lashes. Like other zebras in the show, he is white with black stripes, and has a small tuft of black fur at the end of his tail.
Thurston is a proud zebra, albeit somewhat dimwitted. He is easily spooked, cowardly, pusillanimous, and frightened, so he will run at even the slightest hint of danger. To make matters worse, he is also rather scatterbrained and forgetful, which has even caused him to forget where he lives, requiring the Lion Guard to lead him back safely (after initially becoming confused after Ono asks them to follow him, since, as Thurston pointed out, zebras cannot fly).
He is also very easily bitter, offended, vituperative, uncomplimentary, and opprobrious when the subject turns to the edibility of his own species. Thurston firmly believes that zebras are the tastiest creature living in the Pride Lands, and will become very resentful and arrogant towards anyone who dares say otherwise.
Thurston has also been shown to have a severe dislike of genets, due to their small stature, fur and long tails.
Seeing the Lion Guard talking among themselves, Thurston approaches them and asks them what the problem is. They tell him that they are looking for Flat Ridge Rock, and Thurston asks where that is. The Guard explains that the reason they were asking is that they do not know. Thurston confirms that he does not know the location of Flat Ridge Rock, then asks the Guard where he was going. Ono tells him that he was going back to his herd, and Thurston thanks him and returns to his fellow zebras.
When Lake Kaziwa floods, Bunga decides to create a dam to block the water. Thurston compliments Bunga on his idea, and is later seen receiving advice from Bunga during the song Bunga the Wise. When Kion attempts to put a stop to Bunga's bad advice, Thurston gasps in shock.
However, when the temporary dam breaks, Thurston runs away with several other animals. Although he looks to Bunga for advice, Kion ends up being the one who saves the day by using the Roar of the Elders to force the water back. Thurston cheers with the other animals at the victory.
Thurston and his herd are seen grazing in front of a ravine, oblivious to the fact that the Lion Guard is trapped inside. Ono approaches Thurston, requesting that he moves out of the way so that Kion can use the Roar of the Elders to free the Guard. Thurston points out that he's eating and does not move. Ono finally resorts to diving at the zebras, frightening them. Thurston calls out to his herd, telling them to panic and run. The herd flees to safety.
Thurston is one of the grazing Pride Landers who scatter in fear after Mtoto cries out, warning of a hyena attack. He ends up crashing into one of his herd members before rushing to the rock where the other Pride Landers stand, terrified. He is later seen with the other animals complaining to Beshte over safety issues in the Pride Lands. He points out that zebras are the best-tasting animals in the Pride Lands. He is interrupted as Shauku, Kwato and Gumba rush in to ask Beshte for help. Thurston believes the children are lying, but Gumba assures him they're being honest and that Mtoto really is in danger. When Beshte leaves to save Mtoto, Thurston cries out in fear, asking who will protect him.
When Tamaa the drongo mimics Kion's voice and orders the impalas to move into the Outlands, Thurston hears him, gasps, and remarks that he doesn't need to be told a second time. He then repeats, "Panic and run!" twice before fleeing with a whinny.
Still calling, "Panic and run!", he approaches the Lion Guard. He insists that the Outlands is the only safe place to be while bending down towards Bunga. Bunga pushes his muzzle back, and Fuli asks him where he got the idea. He responds that Kion told him. Kion denies it, but Thurston insists that he heard him and informs the Guard that zebras have the keenest sense of hearing in the Pride Lands. Fuli asks him why he didn't go to the Outlands, and he admits to her that he was going, but did not know that way. Kion has him confirm that he heard, but didn't see him, and Thurston tells him that hearing is believing. When the Lion Guard leaves for the Outlands, Thurston is confused, and says that he thought they weren't supposed to go to the Outlands.
Thurston and his herd are startled, and immediately panic and run. This is seen by Ono, who returns to The Lair of the Lion Guard and gathers up the Guard to help them. With Bunga helping to reign Thurston in, the Guard successfully calm the herd down. When questioned what happened, he explains that a loud 'boom' caused them to panic and run. Ono believes it to be the recent storm, and Thurston agrees that it likely was(after being explained what a storm actually is). After Kion asks him to, Ono shows Thurston and his herd the way home, after Thurston questions how he's supposed to lead when they can't fly. He soon realises what he meant, and chases after Ono.
They are only settled in their grazing grounds for a short time, as Janja, Cheezi and Chungu emerge and frighten him away. Thurston and two other zebras wind up near Maji Baridi Falls, and the Guard manage to locate him later. When Beshte accidentally knocks a boulder, he and the other two zebras panic and run straight into the water. With no other choice, Kion uses the Roar of the Elders to push the water back and save the three zebras from falling off the waterfall. Thurston lands safely on Beshte's back, complimenting it as 'comfy'.
Thurston is briefly seen eating grass during Life in the Pride Lands. He glances with surprise as a butterfly lands on his nose, before he continues grazing. He appears again as Twiga and three more giraffes walk in front of the zebras.
Later, Ajabu begins to graze amongst the zebra herd. Thurston approaches him and questions him, asking if he's a zebra. Upon hearing that the okapi is indeed not a zebra, Thurston exclaims that he knew it. He proceeds to interrogate Ajabu, attempting to guess what he is. He hushes Ajabu when the okapi tries to tell him, wanting to guess correctly himself. Ajabu suddenly shouts "leopard", confusing Thurston further, as he does not know what a leopard is. Ajabu describes a leopard briefly, and Thurston turns and, spotting Makucha creeping towards them, he advises Ajabu to panic and run. The herd begins running in circles, which causes Thurston to crash into Makucha. He begs of the leopard not to eat him, to which Makucha responds that he's after somebody tastier than the zebra and shoves Thurston away. He is highly affronted and proceeds to mutter to himself even after Makucha has gone.
Thurston is in a rush and hurries along a certain path, but he bumps into Bunga and Ono who inform him that they way forward is temporarily off limits. Thurston ignores the honey badger and egret's warning and rushes past the pair in a hurry, disregarding their information completely. Ono and Bunga hope he'll be okay, but Thurston soon calls them over for help, after falling in the thick mud himself.
When the Lion Guard are searching for the Zimwi, they encounter Thurston panicking and running in a small forest. After Kion manages to calm him down, they question what has startled him so bad. Bunga mentions the Zimwi, which disgusts Thurston, who denies being afraid of something which doesn't exist. This pleases Kion, who has been trying to tell his friends that the Zimwi isn't real, and it causes Thurston to laugh just thinking about it. When Fuli tries to ask again what he was frightened of, the zebra accidentally forgets. He soon remembers that it was genets, which sends him into a frenzy again. He leaps away from the Lion Guard, leaving them to continue their mission.
Thurston races to a sausage tree in order to see a group of baboons which he has heard so much about. When The Traveling Baboon Show arrive, they are introduced as Uroho, Mwevi and Mwizi. Uroho jokes with the zebras, thanking them for taking the time not to "panic and run", which Thurston finds amusing because it's true. The show begins, with Mwevi making a flower appear before Thurston's very eyes (which he promptly devours). Once it's over, Thurston leaves.
But once he returns to a patch where food was aplenty, he and several other animals discover that it's gone. When the Lion Guard are called over, Ma Tembo starts to explain the problem. Just as Mbeya starts speaking, Thurston bursts in, angry at the rhino for almost preventing him from telling the Guard the rest of the tale. Repeating what Mbeya told the Guard, they start to consider who could have stolen all the food in just a short period of time. Bunga suddenly suggests a zebra, which offends Thurston. But when the small clump of grass he eats reveals a caterpillar, he panics and runs away, proving that Thurston was not the culprit.
Thurston and his herd get their hooves stuck in some dry mud, after they go looking for the water which is normally there. When the Lion Guard arrive, Kion uses his Roar on a raincloud, dispersing some water which helps loosen the mud, and Thurston is able to free himself. Although Beshte gets swept away, Thurston and his herd members are saved, and he tells his herd that they don't need to panic and run from now on, just panic, as that will be enough.
The character's voice actor, Kevin Schon, revealed that his name is Thurston, making him one of the few characters without a Swahili name. His name is a tribute to Jim Backus, who played Thurston Howell in Gilligan's Island.