Is this some kinda fake? 1 1

[AmeriRuski]

Anyone knows how this can happen? 

[Just Bob]

It was subjected to acid or some other type of corrosive substance that attacked the copper core while leaving the outer copper-nickel layers relatively untouched. There have been quite a few examples posted on this forum over the years.

It was probably more severe than that at one time, but the reeding has been worn off the clad layers.

Edited June 20, 2023 by Just Bob

[Greenstang]

Agree with Just Bob

It has been attacked by acid and copper being softer than nickel, the copper core   
eats away faster.  Have seen quite a few of these.

[EagleRJO]

Yea, acid damage with additional info found here ... https://www.error-ref.com/acid-shrunk-coins/