Monsters vs Aliens

You can get this the first time you start playing with B.O.B. The first segment of chapter 1 will be using Ginormica. The second will be using The Missing Link. The third will be using B.O.B. As soon as you start, there should be a box nearby (which, if you have the tutorials on, will tell you to destroy them with the X button). Don't destroy them. Instead, press B to swallow the item, then press B again to spit it out. Keep repeating this until the Glutton achievement pops. When it does, don't stop, however, as you can get the following achievement as well, by continuing to use the swallow-then-spit method: