What animated show from Netflix had a boy go to another world and meet a little red monster with one horn

Question

A few years ago I remember watching a animated kids show where a boy finds a watch looking thing (I think) that teleported him to a world with monsters and he meets a little bipedal red one-horned monster who got overthrown as king or wants to be king, I can’t remember which. I believe I watched it in summer of 2018 if that helps.

Answer 1

The show I was thinking of was Digimon Fusion.

Mikey Kudo receives the Fusion Loader, creates his own team (Fusion Fighters) and recruits some Digimon partners in the Digital World. There, he learns that Lord Bagramon is attempting to conquer the world by collecting 108 Code Crown fragments and wields the Darkness Loader. Mikey collects some fragments from each zones, but Bagramon steals them and recruits AxeKnightmon. Mikey, Angie Hinomoto and Jeremy Tsurugi are sent back to the human world, but Mikey returns to the Digital World, leaving his friends behind.

From the first episode of season 1:

The story begins with a seventh grade teenager named Mikey Kudo dreaming of commanding a Digimon army. The next day Mikey is harassed by his childhood friend named Angie Hinomoto over standing her up to help the basketball team and his rival named Jeremy Tsurgi demanding a kendo rematch. Mikey spots a dying red creature flickering in static. Wanting to save the creature, Mikey hears a mysterious voice. The mysterious voice presents him with a Fusion Loader. The Fusion Loader absorbs the creature to heal him within the item as Mikey grabs it against his friends' pleas. Mikey, Angie, and Jeremy are then sucked into a portal. They find themselves in a strange world surrounded by a hostile platoon of Digimon under MadLeomon. Mikey, Angie, and Jeremy are rescued by Ballistamon, Starmon, and the Pickmonz before the red creature emerges from the Fusion Loader. The red creature introduces himself as Shoutmon while stating his intent to become the Digimon King of the Digital World. After Shoutmon and his companions fight back against MadLeomon’s troops, MadLeomon absorbs his remaining forces to become Armed MadLeomon. Mikey helps his Digimon friends by using his Fusion Loader to DigiFuse Shoutmon and Ballistamon into an incomplete Shoutmon ×3/x4. After injuring Armed MadLeomon prior to reverting to his usual self, Shoutmon uses the DigiFused Starmon and Pickmonz, in the form of the Sun Sword, to defeat MadLeomon while forcing him back to his original form. A portal then appears. MadLeomon and his minions are recalled by their master named Tactimon. Tactimon is seen conversing with the other evil Digimon over the new turn of events. As Mikey and his friends learn that they are trapped in the Digital World, Mikey, Angie, and Jeremy agree to help Shoutmon and his Digimon friends. Mikey, Angie, and Jeremy are watched from afar by two other groups.

Answer 2

Magi-Nation as per Anime with gems that can summon beasts to fight for the user, one is a purple turtle

Three thousand years ago in the Moonlands, the Shadow Magi Agram was sealed inside the planet's Core by the Core Glyph and the Dreamstones which provided its power. Now he plans to escape by using his Shadow Geysers to weaken his prison in order to bring the Moonlands under his control, and only a Magi known as the "Final Dreamer" can stop him. A young boy from Earth, Tony Jones, is summoned into the Moonlands as he is believed to be this Final Dreamer. He joins forces with the apprentice Magi, Edyn, and the Shadow Stalker, Strag, on a mission to gather the Dreamstones before Agram is set free. Using the Book of Elders, the three travel through the Moonlands while combatting the forces of Agram and gaining an ever-growing collection of Dream Creatures from the Moonlands that they visit.

He's summoned via a ring. The one-horned creature might be Ugger.