Mammoth would be great, but a few that would work there could be Bison / Buffalo Polar - Grissly bear cross Horses Wolves Arctic ( Alaska ) paper from USGS

Mammoth would be great, but a few that would work there could be Bison / Buffalo Polar - Grissly bear cross Horses Wolves Arctic ( Alaska ) paper from USGS - https://pubs.er.usgs.gov/publication/70115138 https://pubs.er.usgs.gov/publication/70115138