Reese Witherspoon mourns the death of Moonie, her canine costar in ‘Legally Blonde’

Moonie, the Chihuahua better known as Elle Woods' faithful companion Bruiser Woods in the "Legally Blonde" films, has died.

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The pup was 18 when he died Thursday, and his death was eulogized by Reese Witherspoon, his Oscar-winning costar, on Friday.

"With a sad heart, I have to let all the #LegallyBlonde fans know that Bruiser Woods (also known as Moonie) passed away yesterday," the 39-year-old wrote. "He was a sweet little Chihuahua who was very loved. I will never forget all the days we spent together ... I'm sure his tail is wagging in the sky. Sending love to his trainer, the wonderful @tailsticks #RIPBruiser"

With a sad heart, I have to let all the #LegallyBlonde fans know that Bruiser Woods (also known as Moonie) passed away yesterday. He was a sweet little Chihuahua who was very loved. I will never forget all the days we spent together ... I'm sure his tail is wagging in the sky. Sending love to his trainer, the wonderful @tailsticks #RIPBruiser ¿¿¿¿

A photo posted by Reese Witherspoon (@reesewitherspoon) on Mar 11, 2016 at 10:16am PST

Animal trainer Sue Chip initially confirmed the pup's death on Instagram on Thursday, sharing a throwback photo of Moonie on the day he attended Witherspoon's Hollywood Walk of Fame star ceremony in 2010.

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"I'm sad to say that this morning in Los Angeles he left us. He was a whopping 18 years old. I remember the day I brought him home as a puppy," she wrote.

On this day - a day of "throwbacks" I give you one of the greatest little dogs..."Moonie" of Legally Blonde fame. I'm sad to say that this morning in Los Angeles he left us. He was a whopping 18 years old. I remember the day I brought him home as a puppy. #RIP #moondoggie #studioanimalservices #moviedog #legallyblonde #chihuahua #chihuahuasofinstagram #reesewitherspoon #famousdogs #bruiser #ellewoods #hollywood #tbt #throwbackthursday @reesewitherspoon @renniedyball

A photo posted by Sue Chip (@tailsticks) on Mar 10, 2016 at 11:06am PST

Chip added that Moonie "was a great little dog that I had the good fortune to train and work on both Legally Blonde films. He lived in L.A. With another trainer from #studioanimalservices and everyone who met him loved him!"

Moonie took center stage in the 2003 sequel "Legally Blonde 2: Red, White and Blonde" when Witherspoon's Elle was inspired by her purse-sized pal to go to Washington, D.C., to work on a bill banning animal testing.

Follow me on Twitter @NardineSaad.