Mark Ruffalo, who plays the Hulk in Marvel's "The Avengers" and has been the subject of "Hulk" movie buzz, reportedly forgot his wallet in a Chicago taxi last Friday. According to TMZ, a man named Ross McHale found it and attempted to get in touch with the actor to return it. The problem was McHale had no idea who Mark Ruffalo was, so he did a quick Google search which then revealed the high profile identity of the wallet's owner, including starring roles in blockbuster films such as "Begin Again," "The Kids Are All Right," "Now You See Me" and "The Normal Heart."

While the information came as an interesting surprise, McHale still didn't know how he would be able to return the missing wallet. Out of options, the kind stranger decided to tweet at the actor about his discovery.

"@MarkRuffalo I have your wallet. Found it in a cab in chicago on Friday. Let me know the best way to get it back to you. Thanks," Ross McHale tweeted on Saturday.

Ruffalo quickly responded gleefully on his page, writing "@Trezeduet thank you! Wow! Another point for the decency in people," then requesting that McHale send him a direct message. "@Trezeduet You are a hero!" he continued in another post.

While TMZ reported that Ruffalo didn't offer a reward, McHale tweeted otherwise. He remarked, "Just for the record, the TMZ claim that @MarkRuffalo didn't offer a reward is false and misleading. He couldn't have been more gracious".

According to ET Online, Ruffalo was serving as a grand marshal at a NASCAR auto race at Chicagoland Speedway in the Windy City. The 46-year-old actor, a hero for renewable energy causes, "also took the opportunity to show his support for racer Leilani Munter, who uses a solar-based energy system in her pit area," according to Fox News. Ruffalo's energy charity, The Solutions Project, is one of the green sponsors of Leilani Munter's Toyota race car.

Ruffalo can be seen in theatres now, starring in the film "Begin Again" with Keira Knightley, Hailee Steinfeld and Adam Levine. Next summer, he will also appear in the much anticipated "The Avengers" sequel, "Age of Ultron."