Choosing words and parts of words that sound evil, dangerous or dark is an important part of creating or choosing an evil name. Use ancient languages, mythology and roots of English words to choose or create a name that is perfect for your villainous canine.
Some words make people feel a certain way. These words, or parts of words, are called phonesthemes. Some examples can include "gl," which makes people think of light, such as in "glimmer," "glitter" and "glint" or "ash," which makes people think of a sudden or violent movement, as in "crash," "smash" and "bash." Keep this in mind while picking or creating a name. Make a list of sounds that make words feel dark, scary or evil.
Authors sometimes use this tactic when creating names for villains. According to an article in "The Week," the word component "mor" sounds dark and evil and makes common appearances in villain names. "Mor" is not only a phonestheme; it's also a Latin root meaning "death." Think "morbid," "mortal" and "morgue." Using root words from other languages is another effective way to build an evil dog name. Latin, Greek, Norse and other relatives of the English language have plenty of evil-sounding words that can strike fear in the hearts of English speakers.
A final suggestion is to find evil characters in mythology or other stories and use or adapt their names. J.R.R. Tolkein used characters from the ancient Norse mythology for names of his characters. For example, one of the heroes of the Hobbit is named Thorin, a name from an ancient poem that means "bold one." Villains in mythology are often named based on bad-sounding root words and can be another great source of evil-sounding names for a dog.