Hey, I've found a lot of Glitches from the PvZ Online Hacked Version:
The Glithes are:
On any level,
Press "Z" to make 1 normal Zombie appears.
Press "C" to make 1 Conehead Zombie appears.
Press:"B" to make 1 Buckethead Zombie appears.
Press "P" to make 1 Pole Vaulting Zombie appears.
Press "N" to make 1 Newspaper Zombie appears.
Press "S" to make 1 Screen Door Zombie appears.
Press "F" to make 1 Giga Football Zombie appears.
You can press as many as you want
For Example: You press "F" for 100 times, 100 Giga Football Zombies will appears.
Remember: You can do this on ANY Level from the link above. Other versions WON'T work!