A person who publicly mocks or criticizes someone for a particular aspect of their appearance or behaviour in order to make them feel humiliated or ashamed.
we should not ever feel disheartened by shamers
she has been the target of body shamers
Definition of shamer in US English:
shamer
nounˈʃeɪmərˈSHāmər
A person who publicly mocks or criticizes someone for a particular aspect of their appearance or behavior in order to make them feel humiliated or ashamed.