  Dirac cloud is in absence in general relativity since the superradiance
mechanism fails to work for Dirac fields. For the first time we find a novel
mechanism to support Dirac clouds, which is independent on superradiance
mechanism. We study quasi bound states of Dirac particles around a charged
spherical black hole in dilatonic gravity. We find that the quasi bound states
become real bound states when the central black hole becomes extremal. We make
an intensive study of the energy spectrum of the stationary clouds for
different fine structure constant $\mu M$, and reveal the existence condition
of these clouds. Our result strongly implies that extreme dilatonic black holes
behave as elementary particles.
