>>46508482 dn EGG_NONE, EGG_NONE ; egg groups
Battle type $05 causes every Pokémon battled by the player to have DVs matching those of a female Pokémon, when possible. Oddly, there doesn't seem to be a corresponding battle type for male Pokémon.
Several Pokémon in Gen II have unused egg moves, which are abilities that can be passed down to a newly-bred Pokémon by its father.
.GotMother:
ld [wCurPartySpecies], a
callfar GetPreEvolution
callfar GetPreEvolution
ld a, EGG_LEVEL
ld [wCurPartyLevel], a
; Nidoran can give birth to either gender of Nidoran
ld a, [wCurPartySpecies]
cp NIDORAN_F
jr nz, .GotEggSpecies
call Random
cp 50 percent + 1
ld a, NIDORAN_F
jr c, .GotEggSpecies
ld a, NIDORAN_M
I don't know what happened but let's just say it happened in August 1999
