A brazen thief stole the only piece of physical advertising for the “Bigfoot is Probably Real” exhibit at the Renton History Museum Tuesday morning.

A man entered the museum briefly behind a woman and her child around 11:45 a.m. and apparently went outside and stole the 10-foot by 4-foot banner from the building. It had been hanging there since the end of October, right before the exhibit opened.

“It was in the back of my mind every time we put one up that someone would steal it, but I thought it would be in the middle of the night,” said Sarah Samson, museum collections manager.

The man took the banner in broad daylight and the theft was witnessed by another woman standing outside.

The suspect is described as a white male, with a slim build, in his 20s to age 30, wearing a black hoodie.

Aside from Facebook and Twitter, banners are the only way the museum advertises its new exhibits.

Ironically, Samson said, the woman and child who came in before the thief said that they found the museum because they spotted the banner.

It costs the museum about $200 to create a banner and this is the first time one has been stolen.

“And it really stinks because this exhibit is open until the end of January and now our banner’s gone,” Samson said.

She doesn’t think the museum has the money to replace it.

The police were given a description of the suspect and did a sweep of the area with no results.