Gene in eggs from chests

All eggs i find in chest always has all stats in ATK, INT and SPD, and ~0 in HP and DEF.

Look screenshots, this creature base ATK is 11 and base DEF is 16. Im just dont understand, why any creature i find have always only ATK, INT, SPD.

Another example, i make screenshot while see egg in chest coz i was sure it will be 500 ATK INT SPD and 30 DEF. And sure it is.