According to People, the Lost Boys actor paid a visit to a Los Angeles tattoo shop as his former co-star was being laid to rest in Toronto.
The emblem on his arm is of the number 222 alongside an elaborate illustration depicting a hot air balloon being lifted into the clouds featuring the name of his son Zen.
The basket portion of the hot air balloon is a peace sign, which was a conversion previously done to cover his ex-wife's name.
"It was a cover-up," Feldman said. "The basket's got my son's name in it. And then I'm putting his eyes underneath it, so it's kind of like his eyes are lifting up the basket which is going into the clouds."
The number is a tribute to Haim, who had '222' tattooed on his body when he was alive.
"On the day of his funeral I felt like I should mark him on my body forever," he added. "Now we're matching."