Slater said he saw the image posted on Instagram by a fan and captured a screenshot of it to share with his 1.7 million followers.
"There is no life I know to compare with pure imagination," Slater wrote, quoting the lyrics sung by Wilder in the children's movie.
"So long, #GeneWilder/#WillyWonka. And thank you for broadening our imaginations as kids. #IveGotAGoldenTicket. And my mom did call me Willy my whole childhood."
It was not received as he intended.
On top of creeping fans out, Slater has been slammed for being "narcissistic".
Many of his followers on Instagram even accused Slater of failing to wait an appropriate number of days following Wilder's death before posting his image.
The image had more than 35,000 likes on Wednesday afternoon (AEST) and more than 400 comments.
"Why Kelly? Why!?," Instagram user wetbraintubman wrote.
"Unethical mate just stick to surfing," user joellebrique wrote.
"Creepy as. RIP Gene," user surfsuckers wrote.
"I'm legit freaked out by this picture @kellyslater," user erikbadapple wrote.
"Uhhh how is making someone else's death about you honoring him. Weak," user joecoomes wrote.
"He's only just died mate very poor taste," user simplyjapanesebonsai wrote.
"Where is the humor in self glorification of you on his death? Do you not have enough attention? We do things for shock value and we do things out of respect. I see Gene's friends from all walks of life and their post and hmmm none of them out of humor have placed their image on Genes most famous role to pay respects with humor! There is no humor in this just self service. Not like you even need the attention," user hoobrah_js wrote.
"I think this is in poor taste, regardless of whether he liked him or not," user paulyweave wrote.
Slater also clarified his post, by declaring he did not mean to offend anybody.
"Someone else did and I just screenshotted it," Slater commented on his own Instagram post. "Zero disrespect intended.
"Simply remembering with humor. I loved this guy. No disrespect. But if you don't offend someone it's not funny."