- Yo-kai Watch: Main game series:
- Yo-kai Watch animation: Recurring Yo-kai
Swelterrier has a similar appearance to Chilhuahua, except that he is red colored instead of blue. The inside of his ears and the bottom of his cape are yellow, but most of his cape is pale pink-ish.
He has the qualities of a well-mannered leader and respects his entourage with ease. However, when Blizzaria is around, he becomes very meek.
Wherever he is and where he goes, Swelterrier can make the place extremely hot.
In most of his anime appearances, he is seen as the leader of the "Hot group" conformed by Sproink, Blazion and Swelton. They are seen together when doing parties. In EP091, they form the 'Atti Soul Brothers' musical group to compete in the White and Red team battle.
Swelterrier and Blizzaria have a very turbulent relationship. Despite Blizzaria trying to hang around with him under believing that Cold and Hot groups are more equal than different, she does not realize she is causing more harm than good -albeit unwillingly- with her ice powers. In turn, Swelterrier seems to panic when Blizzaria encounters him.
Swelterrier first appears in EP081, when he, Blazion, Sproink and Swelton enjoy a party at Nate's House - as suggested by Blazion - and causing extreme heat to Nate and his friends. Nate summon Walkappa to try dowsing the heat, but naturally the kappa cannot stand the heat and wrinkles. The tables are turned when Blizzaria arrives at the house in search of Swelterrier and unwillingly crashes the party with her ice powers. Swelterrier then gives Nate his Yo-kai Medal - encased in ice.
In EP083, in Hailey Anne and Usapyon's quest for Blizzaria -which is the Yo-kai needed for their rocket's cooling system- Swelterrier appears with his group and Blizzaria once again freezes them cold.
In Let's Sing Together! Yo-kai Red and White Song Battle!, Swelterrier and his group participate in the Red and White Song Battle as the 'Atti Soul Brothers', on behalf of the Red Team.
In EP095, Nate first summons him to help Annojoe with his training by having him withstanding the extreme heat. However, the training is thwarted by Blizzaria, who is searching for Swelterrier once again.
In EP125, Hailey Anne, Usapyon, Swelterrier, Blazion, Swelton, and Sproink learn that without her glacial clip, Blizzaria is the Yo-kai Frostina. Blizzaria as Frostina also tells them how she became a Yo-kai. In the end, the hot clan fail to hide her glacial clip causing Frostina to turn back into Blizzaria and freeze them much to Hailey's amusement and Usapyon's annoyance.
In EP153, Nate summoned Blizzaria confront Swelterrier and the hot clan where she freezes them in the process.
Swelterrier rarely appears in the 7th Circle of Infinite Inferno.
Swelterrier can appear ~11,000m in the Infinite Tunnel. He can also be freed from the Oni Crank-a-kai.
As of the Oni Evolution Update, he can also be freed from the Happy-Go-Lucky Crank-a-kai.
Swelterrier can be freed from the Crank-a-kai with a Red Coin, a Red Coin G, or a 5 Star Coin.
Swelterrier can be freed from the Crank-a-kai with a Sawtoakushi coin.
Swelterrier rarely appears on the 13th floor of the Springdlae Business Tower.
Swelterrier can be freed from the Crank-a-kai with 3000 Y-money and 5-Star Coins, more frequently in the S select-a-coin plus.
Yo-kai Watch: Wibble Wobble
Yo-kai Watch: Wibble Wobble
- Befriended (Yo-kai Watch):That was a hot battle lets be friends* Loafing:"Too...hot..."
- Receiving food (favourite): "That's hot!"
- Receiving food (normal):
- Receiving food (disliked): "That‘s cold!"
- Freed from the Crank-a-kai:
- Freed from the Crank-a-kai (Wibble Wobble): "Friendship! Effort! Victory! I'll bring you all these things and more!"
- His Japanese name, "Atsugaruru", is a combination of atsugaru (暑がる,"feeling the heat") and garuru (onomatopoeia for a dog's growling).
- His English name, "Swelterrier", is a portmanteau of swelter and terrier.
- His Portuguese name, "Flamadog", is a combination of flama (flame) and dog.
He is the most recurring S-rank rare yo-kai in the anime series and rarely appears without Blizzaria.
In other languages
- Japanese: あつガルル Atsugaruru
- Korean: 아더월월 Adeoworwol
- Spanish: Lavadenco
- Italian: Kaldokan
- German: Puhdel
- Portuguese (Brazil): Flamadog