In M. Veltman's Diagrammatica, appendix E, one can find the full Standard Model lagrangian. Some sectors (e.g fermion-Higgs and weak sectors) contain so-called Higgs ghosts $\phi^+,\phi^-$ and $\phi^0$.
Are Higgs ghosts Faddeev-Popov ghosts?
why does the Higgs field, not being a gauge field, yield Faddeev-Popov ghosts?
in which sense are they ghosts?