A sheep, a werewolf and a walrus walk into a bar.

Simple chain game...

I post a pic of a famous person, next person has to post a pic of another celeb who has some sort of connection to them. 

.....and away we go! 

Co-starred in the Ocean's movies together...

Co-stars in Marley & Me

both acted in marvel's loki

Co-stars in Withnail & I

married the doctors assistants actor

Barty Crouch senior and junior from Harry Potter

Ronnie Barker was the lead actor in Porridge where David Jason guest starred.

the other half of the 2 Ronnies

another ronnie

Played for Liverpool- played a scouser

Paul Whitehouse played Sir Cadogan in Harry Potter and The Prisoner of Azkaban.

the real star of the Harry Potter movies that other chap above was in

Erm... should be obvious but Bruce Willis and Alan Rickman co-starred in Die Hard.

this Sixth Sense co-star sees dead people

A very tenuous but funny link. Hayley Joel Osment guest starred in a number of episodes of Walker, Texas Ranger.

plays the iconic titular character in the Walker Texas Ranger reboot

Carry on my Wayward Son - Jensen Ackles is co lead of Supernatural with Jared Padelecki.

they starred in Dark Angel together (with Jensen Ackles joining in the second season)

Michael Chiklis - co-starred with Jessica Alba in Fantastic Four and Fantastic Four: Rise of the Silver Surfer

they were two of the best characters in the Gotham tv series

Ben McKenzie co-stars with Donal Logue in Gotham.

"California! Here we come..." they were castmates on The O.C.

Jeff Bridges and Olivia Wilde were co-stars in Tron: Legacy

they co-starred in a little movie about a rug that really tied the room together, maybe you guys haven't heard of it, not sure if its quite garnered a cult status yet, its called The Big Lebowski...

Another fairly obvious one but Steve Buscemi guest starred in a number of Sopranos episodes featuring James Gandolfini (RIP) as the lead.

Giuseppe Rossi is also an American who has Italian immigrant parents

Moving away from movies/TV that they starred alongside

They were both in Blackadder

Both presented QI

GBBO link

IT Crowd, innit.

"Hello IT, have you tried turning it off and on again?"

Because he wrote "I Am The Walrus" and walruses have tusks

Band member narrated for Thomas.