[Atila-Togay]

I never had anything floating in my fermenter. Recently I noticed something growing on my lager after two weeks or so and immediately realized one mistake I made, I had left too much air. First I thought it was pellicle, then lumps started growing so I suspected mold. https://photos.app.goo.gl/98dyHV7JN8r1TkvE7
Now it is well into the fourth week, as I moved the carboy into daylight, some of it sank and I was left with a film and some bubble that look like this :https://photos.app.goo.gl/xaNnjCUmB8paUiAZ8

Is this pellicle or mold or something else? Any ideas? I haven't yet tasted it.

[ynotbrusum]

That is a pellicle forming.

[majorvices]

+1 looks like brett

[KellerBrauer]

That is a pellicle forming.

Yup!

Been there, done that. 

[Saccharomyces]

Acetobacter also can take on that morphology. If the OP has not worked with brett, then it is plausible that acetobacter is the culprit.  Brettanomyces is not native to most homes, acetobacter is found everywhere.  If the beer has a vinegar edge, then it is acetobacter.

[ynotbrusum]

Yes, it definitely could be acetobacter, as well as any number of other nasties (pediococcus, being one).  The OP might want to pitch some Brett into that beer and see what comes of it.  Maybe taste it first to see how vinegar-y it already is, if any, as it could be getting too far gone to fix with a funk mix....If it is acetobacter and it is quite acetic, I would chalk it up to experience and get fastidious with your sanitation regimen going forward.