"NO QUESTIONS ASKED," the sign adds, with an additional reminder that the "REWARD IS $300."
The puppet belongs to Tim Kubart, a Greenpoint resident who plays in a children's band called Tim and the Space Cadets.
Kubart explained that the puppet, Nestor, "is a friend of the band's and he comes out and tells stories and things."
Kubart also teaches music classes to young kids who are also fans of Nestor.
"The kids love him," Kubart said.
Nestor in this incarnation is a relatively recent invention — and investment — for Kubart. He had been using makeshift puppets while he saved up for "the professional Nestor," made by professional puppeteer Frankie Cordero.
Nestor cost a lot of money, Kubart said, which is why he upped the reward to $300 from the initial $100 he promised.
Kubart last had Nestor on Avenue B, where he was house-sitting.
Kubart said he was bringing all of his props in when he realized he left Nestor outside the door. He said Nestor was only outside the door for two minutes, but when Kubart went to retrieve the puppet, it was gone.
After all the publicity and signage, Kubart said he wonders if the person has seen the sign and is undergoing some sort of moral dilemma.
"There might be some sort of moral debate going on right now," Kubart said, laughing. "I wonder if someone's having some kind of moral crisis."
Kubart worried that someone might have taken the puppet and thrown it away, but hopes that's not the case, he said.
"It might be with a kid right now," he said. "I hope the puppet is making the kid happy, if he's with a kid right now."
If you have any information about Nestor, e-mail email@example.com.
Follow Danielle Tcholakian on Twitter @danielleiat