The common tenrec (Tenrec ecaudatus) is a basoendothermic mammal that displays remarkable plasticity in thermoregulation and metabolism during periods of activity and hibernation. For example, tenrecs can maintain body temperatures as high at 28°C during hibernation and remain active with temperatures as low as 12°C. We compared liver proteomes of active and hibernating tenrecs that maintained either warm (28°C) or cold (12°C) body temperatures using label-free protein quantification by LC-MS/MS. We identified 1,526 protein groups in liver and detected 339 proteins that were differentially expressed between active and hibernating tenrecs. Proteins with higher expression in active tenrecs were associated with amino acid metabolism, fatty acid oxidation, and TCA cycle, while proteins with higher expression in hibernating tenrecs included those involved in proteasome degradation, gluconeogenesis, and ketone metabolism. Hibernating tenrecs displayed high individual variability in protein expression that did not differ between cold and warm animals. In contrast, protein expression was consistent within active groups and differed between warm active and cold active animals. Proteins with higher expression in warm active tenrecs included heat shock proteins and antioxidant enzymes, while those upregulated in cold active tenrecs included haptoglobin and translation initiation factors, suggesting that active animals with lower body temperatures may be transitioning into hibernation. Together, these data suggest that metabolic homeostasis may not be tightly maintained during hibernation in a basoendothermic mammal, unlike in boreal hibernating species.