  The newly observed $Z^+ (4433)$ resonance by BELLE is believed to be a
tetraquark bound state made up of $(cu)(\bar c \bar d)$. We propose the
bottomed analog of this bound state, namely, by replacing one of the charm
quarks by a bottom quark, thus forming $Z_{bc}^{0, \pm, \pm\pm}$. One of the
$Z_{bc}$ is doubly charged. The predicted mass of $Z_{bc}$ is around 7.6 GeV.
This doubly-charged bound state can be detected by its decay into $B_c^\pm
\pi^\pm$. Similarly, we can also replace both charm quark and antiquark of the
$Z^+ (4433)$ by bottom quark and antiquark, respectively, thus forming $Z_{bb}$
the bottomonium analog of $Z^+ (4433)$. The predicted mass of $Z_{bb}$ is about
10.7 GeV.
