Someone like the fictional character Uriah Heep.
To be a yes man, in the style of Uriah Heep.
A fictional character, Uriah Heep, in the 1850 Charles Dickens novel David Copperfield, noted for his cloying humility, obsequiousness, and insincerity, the stereotypical yes man.
A person who is servile to the point of self-degradation.