I sometimes like to mess around and have fun with effects in audition, and if you use some of them right you can come out with some really wonky. Here's how you can make your voice sound like a sci fi alien!
First, record whatever you wanna say (which we will turn into an alien voice). Once you have that recorded, right click the waveform track and click "Copy to New". This will copy the file and make a new file appear in the files rack that should be named "Untitled 1". Repeat the process until you see another file appear named "Untitled 2". Create a new multi track, and then drag all 3 files onto the multitrack. go into the 2nd file, and then go to time and pitch>pitch shifter - Modify the semi-tones to -7, then apply. Then go into the 3rd file, open time and pitch>pitch shifter, then modify the semi-tones to +7, and apply. Once you play all 3 files together, it should sound like a funny alien voice!