The Mountain actor on 'Game of Thrones' has the cutest puppy

Icelandic strongman Hafþór Júlíus "Thor" Björnsson is known for playing the terrifyingly large Gregor Clegane (aka The Mountain) on "Game of Thrones." He also holds a world record for keg-tossing, and recently revealed his insane daily diet.

But Björnsson's 15,000 calorie-per-day diet is not what has fans buzzing these days. Instead, we're all obsessed with his Pomeranian puppy. Seriously, look at this thing:

His name is Ástríkur, and the pup even has its own Instagram page under the handle @asterix_astrikur. The two may be the world's most mismatched dog/owner pairing when it comes to size. Despite their physical differences, Björnsson has incorporated Ástríkur into his daily workout routine. 

Scattered among his Instagram videos of weightlifting at the gym are cute snippets of Ástríkur and Björnsson out for daily walks and runs. You can barely spot the puppy among the similarly colored grass, but just look at this adorable workout:

Björnsson captioned the video: "The most cardio I've done in years!! #TimeForPizza #Asterix&Obelix." Ástríkur was named after the loveable cartoon character Asterix. Björnsson refers to himself as Obelix, the fictional pal to Asterix.

You can follow both Björnsson and Ástríkur on Instagram at @thorbjornsson and @asterix_astrikur. Watch the full video of the two running below: