Basilisks

Well, here are my versions of the mythological basilisks. High we have the cockatrice, under it a male basilisk, and on the right a female basilisk, OR two different species. I illustred below all the differences the two theories create:

COCKATRICE
The cockatrice is the first stage of life, born from a basilisk egg, that can be hatched just by a snake or a toad. Unable to fly, it climbs and glides around its territory, catching insects and ther little animals

Male-Female theory
The female cockatrice's bite petrifies its victims, the male's kills in seconds

Two Species theory
The cockatrice's bite kills in seconds, its stare kills.

BASILISK

Male-Female theory
When the cockatrice reach a certain age, it "changes its skin", with an enourmus body coming out of the small shell. Females are twice the size of males, and have the ability to fly and petrify with their gaze. Males are smaller, but fasted, more cruel and lethal, with killing stare, lethal bite and paralyzing rattle.

Two Species theory
Depending on how its killing policy was executed, the cockatrice evolve: if it has killed more beings with its poisonous stare, it becomes a Killer Basilisk (the dilo-like one), if it has petrified the most of them, it becomes a Greater Basilisk (the big one).

Which one do you prefer? I gave the dilo-like ones the role of males because they have the hood and two crests, but the sexes can be shifted.