When angry with someone, it helps to sit down, take a deep breath and relax.
"Silly humor" can help defuse rage in a number of ways. For one thing, it can help you get a more balanced perspective. When you get angry and call someone a name or refer to them in some imaginative phrase, stop and picture what that word would literally look like.
If you're at work and you think of a coworker as a "dirtbag" or a "single-cell life form," for example, picture a large bag full of dirt (or an amoeba) sitting at your colleague's desk, talking on the phone, going to meetings.
Do this whenever a name comes into your head about another person. If you can, draw a picture of what the actual thing might look like. This will take a lot of the edge off your fury; and humor can always be relied on to help unknot a tense situation.
Of course, if one feels inclined to sing...