He actually uses the same pun as the trope title at one point. In the episode "Loyalty to the King", after shaving his huge beard, he introduces himself as "an ice king", is misheard as saying "a NICE king", and then he just runs with it until his true identity is revealed when the beard grows back.
Patience St. Pim, the Elemental Embodiment of ice, also has frost powers. Unlike the Ice King, however, who derives his powers from his cursed crown, Patience naturally controls her magic, giving her greater finesse and ability. For example, her ice structures are more symmetrical, and she can thaw them at will.
Every single Waterbender in Avatar: The Last Airbender and Sequel SeriesThe Legend of Korra. Though it's implied that turning water into ice with bending is an advanced technique. In the latter series' time, it's against the rules for Waterbenders to use ice in the sport of Pro-Bending.
Jack Frost from The Brollys, the literal form of winter itself...and he's not a very nice guy for an ice guy.
Professor Coldheart from the Dic era Care Bears cartoons. Not only was he a blue man with shock white hair, he also used a variety of ice-based science gadgets to freeze people's emotions and make them evil. Except during that one time he made a machine to cover the city in concrete...for some reason. Later aided by his sidekick Frostbite and his aunt, Auntie Freeze.
Danny himself, as well as a tribe of ghost yetis in Danny Phantom.
Man-arctica from Fanboy and Chum Chum, as well as Barry the Ice Monster, who controls the Frosty Freezy Freeze machine.
Also, a big fan of Man-artica, who gains ice powers from a super powerful Frosty Freezy Freeze that freezes him alive for the majority of the episode.
Frosty's Winter Wonderland, the sequel to Rankin Bass'Frosty the Snowman, has a Jack Frost who is more childish and irascible than the other Rankin-Bass Jack Frost mentioned below. Jealous of the children's love for Frosty, he's the main antagonist until he's flattered into a Heel–Face Turn.
The Lilo & Stitch franchise has Stitch's "cousin" Slushy (Experiment 523), a living ice creature whose powers are strong enough that, as seen in his debut in Lilo & Stitch: The Series, can plunge a tropical island into a winter wonderland and potentially cause an ice age. He can even make weapons out of ice in an instant. After his Heel–Face Turn, however, he uses his powers to make delicious Hawaiian shave ice.
Windigoes are winter spirits that feed off fighting and hatred. With enough hate, they could bury an entire land in snow and encase all of its inhabitants in ice.
"Power Ponies": The Masked Matterhorn creates a Slippery Skid that neatly decommissions three henchponies.
In My Little Pony 'n Friends, King Charlatan could fire cold beams from his eyes. By using a machine to amplify his power, he could freeze the entire world.
The New Adventures of Superman: In "The Abominable Iceman", the eponymous beast uses his ice powers to freeze Hawaii, including freezing a volcano solid.
Zane, the ninja of ice from Ninjago. He wields shurikens that freeze things they touch, and his special attack is a giant freeze ray.
Blossom is a heroic example, as her special power is ice breath.
In "Power Lunch", Ace of the Gangreen Gang temporarily gets ice powers from eating ice cream. Apparently, his ice powers are even stronger since he can easily break out of Blossom's ice breath and can even hold the girls in place by freezing them.
Rankin Bass' Jack Frost has the title character, of course, but also a whole kingdom of them living in the clouds, whose job is Painting the Frost on Windows (and everywhere else). Included are Father Winter, their ruler; Snip, who personally cuts each snowflake; the Snow Gypsies, who deposit them on Earth; the Slush Sisters; etc.
King Winterbolt, the Big Bad of Rudolph and Frosty's Christmas in July, is a sorcerer who ruled the North Pole long before Santa Claus settled there. Not only does he cause a powerful blizzard that forces Santa to retreat to ground level during the events of the film, but he was also responsible for the windstorm that occurred during Rudolph the Red-Nosed Reindeer (The same one that almost canceled Christmas).
Speed Buggy and his teenage pals deal with the aptly named Professor Snow and Madam Ice, two megalomaniacs who want Tinker to program their ice robots in a bid for world conquest.
Maureen "Permafrost" O'Connor, a one-time Static Shock character in a Very Special Episode about homelessness, had this as her power.
She was also a little nuts, but not bad, which is good — she was one of the most powerful metahumans they faced and, if she wanted to, she could have put the whole city in an ice age in seconds.
Sapphire from Steven Universe, juxtaposed to her counterpart Ruby having power over heat. Sapphire can turn a motel room into a meat locker or Rose's Garden into a winter scene in a matter of minutes.
Mochi Macchiato from Sushi Pack can freeze her enemies in their tracks and can also freeze anything she touches. This makes her the opposite of Wasabi who has fire-based powers.
Big Bad Arktos from Tabaluga is a living snowman with the power, and ambition, to freeze nearly anything and everything.
Possibly the most common power in Winx Club: besides the most common user Icy, we have Belladona of the Ancestral Witches, background character Alice (or so we're told), Aurora of the Major Fairies of Earth, and Aurora's army the Artic Fairies.
Omi of Xiaolin Showdown can adapt his Orb of Tornami Shen Gong Wu to become this.
Snow Miser from The Year Without a Santa Claus rules the North and wants the whole world to be cold, in contrast to his brother, Heat Miser, who's... basically the opposite of all that.
Friends call me Snow Miser! Whatever I touch
Turns to snow in my clutch!
Ha ha... I'm too much!
In the first episode of Young Justice (2010), several ice-based enemies (Mr. Freeze, Icicle Jr., Killer Frost, and Captain Cold) attack separate cities at once. The League finds this an unlikely coincidence and goes to investigate. It turns out that they were planning to meet up with Icicle Sr. in prison and planning a prison break. In a later episode, when North America is paralyzed by freak ice storms, Batman and The Flash go straight to question the previously established ice villains.