The mongoose lemur is fairly small with soft bushy fur which is grey in colour with lighter bellies. The females have cream coloured cheeks, young males are born with white cheeks and beard which then turn red as they mature. Both males and females have bright red-orange eyes.

Depending on variation between wet and dry seasons, this lemur can switch from being active during the day time to being nocturnal. Their main diet is fruit but they will also eat flowers and nectar if available. Females give birth around mid-October and remain in small family groups. The young will stay with the group until it is about 2.5 to 3.5 years old. If the group encounters another family group they may be very vocal, making aggressive threats and charges, along with scent marking their territory. Humans are majorly threatening the habitats of these lemurs due to demands for more space to grow crops, pastures and producing charcoal. This lemur is sometimes classed as a crop pest by local people and can sometimes by caught in hunting traps, despite being protected by law on the Comoros Islands.