I looking around the internet and found (possibly) information of series 4 Mixels
The link where I found the information
According to that website, Nurp-Naut is part of a tribe called the Orbitronz which looks like a tribe based on space plus Nurp-Naut has a second face! Glowbert is part of a tribe called the Glowkies which is possibly a tribe that could possibly glow-in-the-dark. And looks like Burnard happens to be the 4th member of the Infernites.
Remember that this information may not be true. But Nurp-Naut does have a second face.
Nurp-Naut's second face.