  Itinerant ferromagnets constitute an important class of materials wherein
spin-polarization can affect the electric transport properties in nontrivial
ways. One such phenomenon is anomalous Hall effect which depends on the details
of the band structure such as the amount of band crossings in the valence band
of the ferromagnet. Here, we have found extraordinary anomalous Hall effect in
an itinerant ferromagnetic metal LaCrSb3. The rather two-dimensional nature of
the magnetic subunit imparts large anisotropic anomalous Hall conductivity of
1250 S/cm at 2K. Our investigations suggest that a strong Berry curvature by
abundant momentum-space crossings and narrow energy-gap openings are the
primary sources of the anomalous Hall conductivity. An important observation is
the existence of quasi-dispersionless bands in LaCrSb3 which is now known to
increase the anomalous Hall conductivity. After introducing f-electrons,
anomalous Hall conductivity experiences more than two-fold increase and reaches
2900 S/cm in NdCrSb3.
