Dwarf planets

Dwarf planets are celestial body resembling a small planet but lacking certain technical criteria that are required for it to be classed as such.It is not neceserry that all the dwarf planets wont have any satelite,Eris another Dwarf planet beyond pluto has it's own satelite named dysnomia.The photo on the right shows another Dwarf named Haumea,which has it's own 2 satelites.

what are the feature of a dwarf planets?

It is in orbit around the Sun.
It has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape.
It has not cleared the neighborhood around its orbit.
And it is not a satellite.

Is there anything smaller than dwarf planet?

The dwarf planet Eris —once thought to be the largest body in the solar system beyond Neptune's orbit—it may actually be smaller than Pluto,but astronomers still beleive Eris 25 percent more massive than Pluto.