In all versions of the storyline, SPY Fox must use the spy putty on Gilbert's invitation to the party on the S.S. Deadweight in order to gain entry to the party. SPY Fox must first however distract Gilbert by getting him to buy him something on the shelf (all the trinkets there are too high for Gilbert to reach). While he is distracted with this, SPY Fox must use the putty on Gilbert's invitation in order to create a perfect copy of the invitation. SPY Fox must then give this copy to the weasel doorman, so that he will be allowed to go to the party anytime he wishes.
According to Professor Quack, various toy makers stole his idea for the SPY Putty when they tried to sell off silly putty in toy stores.