  We study the theory that contains two spin-2 fields. This theory can be
regarded as a simplified version of higher spin gravity in AdS3. It can be
formulated either in the first order formulation or in the second order
formulation. From the first order formulation we construct the black holes in
the theory and study the thermodynamics of this black holes with the help of
dual holographic OPE. From the higher spin point of view, this black hole is
most naturally regarded as a black hole with a spin-2 hair. In the second order
formulation, we obtain an action for the metric and extra spin-2 fields and
analyze the corresponding black holes. Even though for some simple cases, the
conventional notions, such as the horizon, may help us to read part of the
information of the black hole, they break down in generic cases. On the other
hand, the action in the second order formulation could be rewritten in the form
of a decoupled AdS3 bi-gravity. Moreover, the entropy of the black hole with
the spin-2 hair could be reproduced from the AdS3 bi-gravity in the Euclidean
path-integral formalism.
