Instagram Round-Up: Jim Harbaugh Challenges a Walrus to a Push-Up Contest, Plus 14 Must-See Posts

In STACK's weekly Instagram roundup, the Atlanta Hawks host a wheelchair basketball clinic, Jim Harbaugh faces off against a walrus and more.

Each week STACK scours the Instagram accounts of the world's best athletes to bring their most interesting posts to you. This week, the Atlanta Hawks host a wheelchair basketball clinic, Sio Moore and Co. take out some jet skis, and Jim Harbaugh faces off against a walrus.

15) Antonio Smith
Caption: Love this kid's sense of humor like mine.

14) Al Horford
Caption: Wheelchair basketball clinic here at the Arena. #Hawks

13) Antonio Brown
Caption: Drive ! @jumpman23 sneak peek on push press today !!!

12) Julio Jones
Caption: Acting up at #visa photo shoot

11) Sio Moore
Caption: When you can do things you never imagine #Blessed @jjwilcox_19 @king8jamie

10) Ty Lawson
Caption: #smurfgang t-shirt line coming soon what y'all think

9) Earl Thomas
Caption: Had a great workout with my teammates ...#hookem #UT #love

8) Marcelo Vieira
Caption: Feliz dia de los padres !!!!

7) Chad Johnson
Caption: Cinco Muscle Ups‼️

6) Al Jefferson
Caption: #TBT "Al Jefferson was surrounded by family members when he was taken by the Celtics in the 2004 draft." From today's @SportsIllustrated article titled "Al Jefferson, a low-post whiz, brings sunshine to Charlotte." Visit for the link to the article!

5) Nate Robinson
Caption: #stateofnate @teejayregan #enoughsaid #holdat

4) Jim Harbaugh
Caption: Push-Up Contest. Jim Harbaugh vs. Walrus. #NFLOffseason

3) Chandler Parsons
Caption: Cool little bike ride with the squad!

2) Thiago Silva
Caption: Amigos são como o vento as vezes perto , outras vezes longe +eterno em nossos corações !!!! @neymarjr

1) Udonis Haslem
Caption: S/O to my brother @kingjames for these custom made WWE championship belts. It was WWF back in my day and Junk Yard Dog was da realist. Lol. On the floor or off We Fight! #heatles #3xChamp #back2back

Photo Credit: Getty Images // Thinkstock