Yush, Toshi.
In addition to buying the item, you have to complete a quiz/quest.
The item should cost more than 200 creds though.
Some rules that can go along with it...
1) You may not get glitched pets/doubles.
2) Though, you may use one of the uses to delete one of the other doubles, which gives you another chance to get the creatu.
3) If you do delete a creatu, it costs you TU, but you still have one 'grab' left.
4) You may only grab/delete a creatu every 24 hours/reset.
5) You may not trade the CS item.
Of course, you get 1 delete and 1 grab per item buy.
Eh. Edit.
Some more ideas.
- Once you do get one free 'grab', you must complete (#) of quests in (#) of hours, to get (#) of points.
- Those points can get you the (%) rarity of the pet you want to grab.
- If you fail the quest, you can retry, but you have to pay TU.
- If you fail the quest and don't retry in (#) of hours, you get "delete" points instead, to delete creatu from the forest/graveyard/etc.