Kieran Valentine is a 2012-introduced and cartoon-only character. He is a vampire with immense powers and a narcisstic, cruel personality that make him dangerous to be around. He plays a sick game of seducing girls, sometimes by hypnotism, and then intentionally breaking their hearts to add to his "collection", which makes him gradually grow stronger. The only one who ever escaped his influence, if only by coincidence, is Draculaura. A second attempt to obtain her heart even resulted in him losing his entire collection and with that all his powers. Valentine likes to act like a smooth and in-control gentleman, but when in trouble, all he'll do is cry for his mother.
He is voiced in English by Jonathan Lipow.
Valentine is mischievous and scheming, using his quick thinking and allusive facade to his advantage. Like most vampires, he is very arrogant and aristocratic, he sports a fake southern accent and a masked personality to get what he wants. He often convinces girls he's created Valentine's Day just for them in order to win their hearts.
Recently, Valentine reappeared in the comic book I Only Have Eye For You, where he appeared to have turned over a new leaf and, and attempted to help other monsters find romantic dates for the Fraidy Hawkins dance, and tried to make it up to Draculaura and Clawd by paying for their date. His efforts didn't quite succeed as he planned, but everyone ended up with a partner regardless.
He has pale skin, shaggy hair with black and red stripes and bright pink eyes. His features are strikingly handsome, enough to make any monster girl fall in love with him.
Valentine lives in a mansion with his mother, who appears very protective of him. While Valentine likes to act like he's mature enough to act without her interference, he is not and will look for her aid if he loses control of the situation.
Three Clouds are Valentine's constant companions and accomplices. They revel in the hurt Valentine causes, but aren't too bothered with laughing about their master's misery if the situation occurs.
Though Valentine has the charms to catch the interest of most girls and the hypnotic powers to grab the interest of the rest, Valentine is only interested in them for their hearts.