In a recent article in the New Yorker ("Hogs Wild"), Ian Frazier writes about an urban-legendish monster boar that was shot, photographed, and shortly thereafter buried. The lack of concrete evidence inspired descriptions of an ever-bigger pig until it came to be known as ... tada! ... Hogzilla. (The boar did prove to exist, and did indeed prove to have been huge, though not quite up to the size of legend.)
The suffix -zilla is another one of those morphemes that falls out of reparsing an existing word. The meaning seems to be "monster." So Hogzilla is a monster hog. Something like truck-zilla would be a monster truck. Here are some examples I found using Our Friend Google:
- ForumZilla a kind of meta-forum for finding forums. They use a lizard logo.
- Blogzilla. Nice graphic.
- Gozilla, "monster downloads."
- Nanozilla, in the cleverly titled article "Nano-zilla strikes Tokyo."
Update 28 Jan 2006 I just thought of another: bridezilla, which per Paul McFedries is "a bride-to-be who, while planning her wedding, becomes exceptionally selfish, greedy, and obnoxious." That is, a bride-monster.
The suffix -zilla is handy, because as far as I know, we don't have a particle in English that we can add to a word to create "big version of." We have diminutives -- dog, doggy -- but no, uh, what? increasative. (Actually, it's called an augmentative.) In Spanish, there are a handful of augmentatives, such as -on and -ota, to name two. Una caja is a box; un cajón is a big box, etc. (For the curious, more on Spanish augmentatives to be found here.) Of course, -zilla isn't just "big version of"; it's "unprecedently enormous version of": the monster version.
And whence this term, anyway? I can't say definitively, but a very good bet is that it began with the movie Godzilla. That's in itself a slightly strange word, an Anglicization of the Japanese word Gojira, with an extra -d-. (One etymology posited here.) Given that Godzilla is an unprecedently enormous lizard, it's not a stretch to break the name on boundaries that make sense in English (god+zilla) and reuse the suffix-like part.
A note on Mozilla, the umbrella name for the browser foundation. The foundation uses a lizard as its mascot, but according to some purported diary entries from Jamie Zawinski, the name's originator, the name came first as a portmanteau of something like Mosaic+killer, Mosaic being the browser guts on which many a commercial browser was originally based. And in an interesting twist, some uses of -zilla do not directly mean "huge"; they instead echo the Mozilla name and suggest some affinity with that browser or its community, such as Bugzilla and podzilla.