It is a very complex procedure that requires going into the games programming.
The Grox hack will allow you to play as the Grox creature or other creatures that are made of parts that do not allow you to save, therefore this is also a hack that allows you to bypass the save check (huge parts can be saved with this but revert to their original sizes).
1) Download Grox creature or the other creatures below to your desktop by right clicking on the image and selecting save image as.. This would be the creature you wish to play.
Download The Grox:
3. Select the stage you want to play at (has to be after creature stage, so the lowest level of game play would be tribal stage).
4. Choose your diet, I would suggest carnivore as the grox are carnivores. When you have the choice of creatures, click on the create your own.
5. You have to follow the next few steps exactly or this will not work.
You should first name the random looking blob creature.
6. Add a random head to the blob creature.
7. Save the creature you just made by clicking the SAVE button and not the SAVE AND EXIT button. YOU MUST DO THIS STEP OR YOU WILL NOT FIND THE RIGHT VALUE!
8. Open up Tsearch, select SporeApp.exe and search for the value: 0
9. Now remove the head from the blob creature.
10. Now refine the search for the value: 1024
11. Now refine the search a few times by adding random heads and removing them, just remember that if the creature has a head, no matter how many heads it has, the value should be 0 and not changing and if it has no heads (mouthless) it should be the value of 1024 and not changing. You should end up with one value after refining about 3 or 4 times. Add it to the right side of Tsearch by double clicking on it.
12. Make sure your blob creature has a mouth and freeze the one value you refined at 0 by clicking on the freeze button () above the value on the right side.
13. Now drag the Grox image file over the blob creature in the creation screen (same as loading the hacked creatures from the hacked creature section). It will ask you if you want to save your creature, you dont have to if you dont want to.
14. Now the Grox creature should be loaded.
15. Now you can click on the Save and Continue button, if you have done it right it will continue to the next step (if you get a message saying Creature Cannot Be Saved you should redo the searching for the value of 0 and 1024 with a new blob creature).
Link to website- http://www.sporebase.com/9.html