Here are all the possible Pokemon you can get from the Mystery Egg in Route 3
Variable 0: Azurill
Variable 1: Aron
Variable 2: Absol
Variable 3: Togepi
Variable 4: Sneasel
Variable 5: Dhelmise
Variable 6: Joltik
Variable 7: Axew
Variable 8: Mienfoo
Variable 9: Pawniard
Variable 10: Trapinch
Variable 11: Drilbur
Variable 12: Cottonee
Variable 13: Darumaka
Variable 14: Solosis
Variable 15: Starly
Variable 16: Larvitar
Variable 17: Larvesta
Variable 18: Mareanie
Variable 19: Stufful
Variable 20: Wishiwashi
The Variable Number is for people who wish to debug a mystery egg Pokemon for their Mono Runs or for people who want a specific Pokemon