Cut the Rope Cheats :
TuMmy Tester Achievement
For this Achievement you'll need Om Nom to open his mouth 10 times in a row. Select Level 1, Cardboard Box and select level 4 of the Cardboard box. Cut the Top, Left and Bottom rope at the same time, leaving only the right rope. The candy will dangle and Om Nom will open his mouth as it passes by.
Alternate technique by Shua: On level 3-9, there are sliders. On the bottom slider, just get close to the Om-Nom then away from it ten times. This is the easiest way to get that achievement.