It seems most people can't, as you almost never hear anyone pronounce, or spell, the word asterisk correctly.
An asterisk is a typographical symbol, and it looks like this: *
For some reason, most people refer to the asterisk as an "asterix".
Asterix looks like this:
Do you see the difference?
One is a small star-shaped punctuation symbol, the other is a cartoon Gaul with a winged helmet.
It isn't just individuals that make this mistake, large companies often do too. Here's a bit from a current NatWest competition entry form:
"Fields marked with an asterix are compulsory". Ok, fair enough. But not a single field is marked with the famous mustachioed French man, so it seems they should all be optional, but they're not.
As if this common failure wasn't bad enough, it seems most people are actually guilty of a spectacular double-fail where the mighty asterisk is concerned. Not only do they think it is called an asterix, they also think that the cartoon character of the "same" name looks like this:
This individual is not an asterisk. He is not an Asterix either. He is called Obelix.
Here's a handy guide you can print out and keep: