At first, you find the turtle on its feet. Deleting a line or a section with it flips it on its back with its every limb and head hidden under the shell. Every move after that, the turtle gets one of its limbs out (ending with its head) while staying on its back.

Once the turtle gets all of its limbs out, it flips back on its feet.

You can only collect the turtle by deleting a line or a section with it while it is on its back.

Thus, you have to delete the turtle by flipping it and then delete it again within 5 moves to collect it. Otherwise, it's back to step one.