Python: Instance class mutation

Question

I have two classes:

class Egg:
    def __init__(self):
        self._color = 'White'

class Larvae(Egg):
    def __init__(self):
        super().__init__()
        self._color = 'Transparente'

To illustrate ...

So, in my code I have an Egg instance. When it's time I would like transform them into Larvae instances. I can create a Larvae instance and hand copy informations about a "previous" Egg instance. What does Python offer for something like that? For "mute" an instance in instance of subclass of its class?

Edit: As commented below, OOP in this question is not good way to do the wanted behavior. So, keep this in mind when reading answer

Answer 1

How about using a state-based approach?

class Ant:
    def __init__(self, state='egg'):
        self.state = state

    @property
    def color(self):
        return {
            'egg': 'Transparent',
            'larvae': 'White,'
        }[self.state]

    def hatch(self):
        if self.state == 'egg':
            self.state = 'larvae'
        else:
            raise Exception('Cannot hatch if not an egg!')