To get the T-Rex gauntlet achievement, you have to three-steak (finish the level with all three steaks intact) level 2-19 using only two items - crushers and portal twins. This guide will show you how to solve this problem in one single picture.

• Start by collecting all the available coconuts before the first dinosaur comes into the level. You don't have to wait for each coconut to be collected, just click on them as fast as you can, and your character will get them all.
  
• Use the coconuts you have to set up first crusher near the beginning of the pathway that dinosaurs use (see the picture below). Shoot at the small dinosaur to kill it, while waiting for the next coconut to appear.
  
• As soon as you get more coconuts, collect them and continue building crushers as shown on the picture. Build the ones closer to the beginning first, then progress towards the end.At the end, build a teleport near the very end of the pathway.
  
• Whenever you are a coconut or two short, jump to the middle of the level to shoot at dinosaurs (exact position is shown in the picture). After building everything, feel free to stay there and destroy the small (crushed) dinosaurs until they are all gone.
  If needed, re-position yourself near the teleport for a time, but get back as soon as that part of the path is clear again.