When playing any level with Motley if you press q,w,e in quick succession he will bite the sheep nearest to him causing it to jump over any obstacle.
Adam Half Pint can drop pints to get the sheep to follow him. Apparently you have to type pint really quickly while holding down Alt + Shift.
The Modern Pastoral sheep can be made to follow any character by chasing them around the same object five times! Try this one at your own risk. If doing this one with Shep you run the risk making him puke.
Cheat Mode
Simply hit ESC to bring up the Main Menu and type one of the words below to enable the cheat. If successful, the menu will disappear (non-US versions only) and the cheat will be activated. Type slowly and carefully to ensure correctness.
Cheat Code - Granted Wish
FatSheep - Sheep Grow to 150% Their Normal Size
MiniSheep - Sheep Shrink to 1/2 Their Normal Size
PooSheep - Pastroal Sheep Poo Instead of Graze
CancelCheats - Deactivate Cheats
Note: Only the "PooSheep" cheat will work in the US version of Sheep. The other cheats were added into the game AFTER the US version was complete.