The drops depend of the monster you've killed, but with monster cards you'll get several data egggs per monster, sometimes a mercenary egg or a boss card too. A few chances to get either backups disks or evoluters. You'll also get for each monster one or more food items (MC2: fries, MC5: hamburger etc). With MC4, you will have a lot of Cores (character bound). MC7 give you a evoluter or more with almost each card.