NCIS Superlatives! Show’s Longest Running Castmember Names Class Clown, Life of the Party and More (Exclusive)

NCIS' longest running castmember, Sean Murray, is handing out some awards to his beloved costars!

During an exclusive conversation with PEOPLE about the franchise's 1000th episode milestone on April 15, Murray, 46, gave his costars some classic yearbook superlatives in celebration of the bond they've formed over the years.

When asked who he would consider NCIS' "biggest class clown," the actor ponders the question before laughing and giving the award to "my brother, Mr. Wilmer Valderrama."

"He's a steady stream of hilariousness for myself and many others, so we have a lot of fun shooting together, and I see that guy offset all the time," he shares. "He's a lot of fun. I'm going to give that one to Wilmer."

Though Valderrama may tickle Murray's funny bone, he says that his costar Katrina Law has the most nurturing disposition out of the group and would consider her the "biggest mom or dad" of the crew.

"She's a mother herself with a young daughter, married," Murray says, explaining that it was a "wonderful" quality he noticed early on about Law. Despite the long hours and hard work she puts into the show, Murray says that she is easily "one of the most dedicated mothers I've ever seen and ever known."

"It's pretty amazing to see," he gushes. "We're working our butts off and for those two or three minutes that we have between takes or setups, she's on FaceTime calls with her daughter. And to me, that's something that's really important and special."

That motherly energy doesn't just extend to her daughter, Murray says that she shares that "sort of vibe" with everyone on the cast. "She cares so much about everyone and such a warm person," he adds.

Though Law snags the accolade for biggest mom or dad, Murray has a different contender in mind for "biggest sweetheart."

"Diona Reasonover for sure is the biggest sweetheart ever," he chuckles while recalling the first time the crew met her on set. "She came onto the show and everyone fell in love with her immediately. And I'm not just talking about viewers, I mean us, as people working with her, immediately."

"Diona's a very special person, a very close friend of mine," he adds. "Diona's amazing."

With Law and Reasonover on the cast, Brian Dietzen, who's named as "most-accident prone" by Murray, is sure to have tons of support by his side when he scrapes a knee or bumps his head.

"Oh, poor Brian ... I love that guy to death," the Hart of the West alum shared before recalling an accident Diezten had on set. "I remember years ago we were shooting on a location, and there was a small tree, and it was very windy and a huge amount of wind came in. What happened is, a branch had broken off the tree and it had come down and sort of hit Brian in the arm."

Years after going arm-to-arm with a tree branch, Dietzen still hasn't been able to shake the label. Murray reveals that he has another hiccup while filming the season 21 finale of NCIS while filming an action packed scene.

"Brian bumped his head pretty bad," he continues. "So this is why, just off the bat, I feel like I've got to give that to Brian. And I don't want to take away from his grace either. He's a graceful man and a hell of a performer and a hell of a physical per medium."

After naming class clown, mom or dad, biggest sweetheart and most-accident prone, Murray gives out one last award to Gary Cole, who he considers as the "life of the party."

Though he couldn't get into the specifics of Cole's accolade, Murray claims the superlative is well deserved. "Gary is the most... He's just the most perfect performer," he says. "I don't know, I can't even really describe it. I just want to give it to Gary. I want to give it to Gary because he deserves that."

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer​​, from celebrity news to compelling human interest stories.

NCIS airs Mondays at 9 p.m. ET on CBS.