What should i leave my girlfriend in her luggage as a surprise (leaving for 5 weeks)?

Hey, my girlfriend of two years is leaving for greece in a few weeks, for a total of 5 weeks. I know i'm going to her house to help her pack, so do you have any ideas of something sweet i could secretly put in her suitcase (wrapped in clothes or w.e) so she finds it when she's in greece? I was thinking of putting this little stuffed lamb, which ive had since i was born. It's the most representative thing of me, however i'd be crushed if he somehow got lost :/. Any suggestions?