I’ll let the image illustrate my question. I have spent so so many hours trying to firgure this out! Please guide me in the right direction. If I’ve understood it correctly, the material for the player character is a rectangle that would fit different character assets - and I have no clue why the engine keeps track of the old character shape when I deleted everything in the new sheet and imported a totally different looking character.
… What am I doing wrong? 
I have tried to reimport. Should I reimport the .tga or the .psd? I asks for the .tga by default it seems, but as I reimport the .tga - the material file for the sprites goes blank, like this:
But as I click the material, the content is all there with the new sprites.
And player disappears from the game like this
if you did it as a tga and you re getting the old alpha channel i d suspect you re saving your tga as 24 bit and not 32 bit, ie no new alpha channel to overwrite the old one
Yeah check in photoshop if there is an alpha channel, most likely it is still there from the chicken.
I saved as 32 bit, but still getting the same problem.
Do I need to change the material somehow? This is how my setup looks:
I understand this is a beginner question, but I would really appreciate some hints as I am stuck here 
have you checked the alpha like others said above because that is most likely what it is
