"The last picture I ever took of my little boy, I love you endlessly. I miss the warmth you brought to our home and our hearts. Not a day will pass that I won't think of you and thank you for the joy you gave us. Rest In Peace my love," Moretz wrote on Instagram. The photo was met with plenty of supporting messages from fans offering condolences.
Moretz also shared a different photo of Fuller on Tuesday to announce his passing to her followers.
"Rest In Peace my dear dear Fuller I love you more than you know. You've been my protector and best friend since I was a little girl and I wish the end didn't come so abruptly but I know you're at peace now. I love you I love you I love you you will forever be missed," she captioned the post.
Everyone grieves differently — and for plenty of celebrities, sharing photos and memories of their pets seems to help with the grieving process. Demi Lovato recently shared a heartfelt tribute on the anniversary of her dog's death.
If you have a pet, maybe give them a little extra love tonight in honor of Moretz and Fuller.