My guess is that Unc is partly responsible for the people turning into hybrids and he may ...

My guess is that Unc is partly responsible for the people turning into hybrids and he may have developed something that causes it. Which is why he takes some of them in while at the same time puts a distance between him and them. Or the phenomenon wasn't caused by him but he was studying and experimenting on it

Whatever Little A opened may have exposed him to whatever triggers the mutation. Fluffy was there too when Little A opened the box and got turned into a hybrid from an actual dog (which is why he's called Fluffy and not 'M' or 'K' like other livestock). Little A was being monitored and checked up on to make sure he didn't develop animal characteristics as well.

Unc probably turned into a hybrid which was why he was on the run. Little A may have immunity to the mutation and that's why the organization tricked him into moving to the farm to experiment on him.

Ngl I just wanted to goon...