Welcome to a new series of mine, dealing with specific points I think skeptics should focus on when making arguments. Today's entry: It's populations of organisms that evolve, not individuals.
Yeah, animations of organisms changing over time are a nice way to show the history of a lineage, but possibly thanks to Hollywood, comic books, and so forth, (alongside Creationists using such instead of textbooks in their inane arguments) there's a lot of Creationists who think evolution is about magical transformations randomly happening to individuals. This, of course, is complete bumpkis.
Those animations? It's better to think of it as the net averaging of a lineage over the course of generations. Mutations and combinations that result in a big difference are pretty rare. Usually, evolution takes the form of very small differences: For example, a gene that makes teeth a little bit longer shows up and is beneficial. The slightly longer-toothed individual has more kids than average, who have more kids than average, and so on until that gene is commonplace in the species. From that changed population, a new, different trait may take root, and so on. New traits may make old, previously neutral ones more beneficial than usual, so those propagate, etcetera.
Nowhere is the process directed or able to foresee the future. Steps don't have to occur in a particular order. Older "models" of a species can stick around for extended times if they're isolated and/or still competitive enough. Nowhere is there a requirement for a "wonder monkey" that shows up as a paragon of momentous change, like they do in the comic books. Sorry, X-Men hopefuls, it's an incremental process, and advantages will generally be small.
Metaphor time, since Creationists are fond of bogus probability: A species's evolution from one form to another isn't settled in a single pull on a big slot machine. It's more like some of those videogame slot machines that allow you to lock individual wheels. Now imagine you've got millions of people playing the same game, and when one locks a beneficial wheel, that benefit spreads to the other players. To add to that, there's several ways to win the jackpot. There's no individual wildly improbable act being done. When you've got millions of players, one of them getting a favorable turn of the wheel is hardly extraordinary. When those small successes are allowed to persist and spread over generations, progress is expected.
So, to summarize: An individual organism getting a big improbable change is the stuff of comic books, not evolution. I think any Creationist who makes such an argument should be ridiculed for not knowing the difference between the beliefs of Magneto and real world scientists.