  We apply a methodology to build a sample of extreme emission line galaxies
(EELGs) using integral field spectroscopy data. In this work we follow the
spectroscopic criteria corresponding for EELG selection and use the MUSE Hubble
Ultra-Deep field survey, which includes the deepest spectroscopic survey ever
performed. Objects in the primary (extended) sample were detected requiring a
rest-frame equivalent width EWo $\geqslant$ 300A (200A $\leq$ EWo $\leq$ 300A)
in any of the emission lines of [OII]$\lambda\lambda$3726,29,
[OIII]$\lambda\lambda$5007,4959, or H$\alpha$. A detailed closer inspection of
the spectra of the candidates selected has been performed on a one by one
basis, in order to confirm their classification. For this sample, the line
fluxes, physical properties and chemical abundances of the EELGs have been
derived as well as their spatially resolved structure and kinematics. Four
(five) of the galaxies in the primary (extended) sample, $\sim$57$\%$
($\sim$83$\%$), were spatially resolved. Three (none) of them present a clear
pattern compatible with rotation. We have shown how our entire EELGs sample
share the same loci defined by high-redshift galaxies (z $\approx$ 6-8) for the
mass-metallicity relation, illustrating their role as local analogs.
