Does anyone know what these pieces are from ?

T octopus

I am not sure what these pieces are from

annalisa79

From left to right:

First minifigure:
https://www.brickowl.com/catalog/lego-axel-diver-minifigure-350752

Second minifigure, I think the parts are from different minifigures, the torso belongs to this:
https://www.brickowl.com/catalog/lego-wolf-guy-set-71010-1

Third minifigure (but different face):
https://www.brickowl.com/catalog/lego-city-police-officer-minifigure

Fourth minifigure:
https://www.brickowl.com/catalog/lego-octan-worker-with-blue-shirt-with-small-octan-logo-and-oil-nametag-blue-legs-and-blue-cap-minifigure

Calibrick

@t octopus, the easiest way to figure out a minifig you don't recognize is to see what looks the most unique, e.g., the torso, the legs... and put in some keywords (like the octan worker, "oil" would have been perfect), then filter down the results by color (blue, in this example), and type (minifig, torso). From there, you can see what minifigs that piece is a part of and find your minifig. :-) That's the easiest way I've found if I have zero clue at all.