A famous chalk figure on the hillside was adorned with a facial mask, apparently referring to the coronavirus.
Cerne Abbas Giant is said to have undergone an unauthorized makeover on Friday.
Local resident Kevin Knight, who tweeted a photo of the alteration earlier, said it “really cheered up the villagers.”
The National Trust, which manages the Dorset protected site, has said it does not encourage damage.
The 180-foot (55 m) old naked figure is normally not accessible to the public, to avoid damage and erosion.
It has been unofficially modified several times before.
The penis was adorned with petals and leaves in 2019, while two years earlier the name “Theresa” and a tennis racket had been added on different occasions.
Knight tweeted, “It’s great to see the giant from Cerne Abbas practicing social distancing, wearing his mask and keeping the villagers up.” “
He added, “It made some of the faces of the elderly who protect themselves and self-isolate smile. “
The modification looks like a hand drawing, tweeted Tuesday by Department of Defense archaeologist Richard Osgood.
Osgood said his “prophetic” sketch, with the words “stay safe”, was a “bizarre coincidence”.
The National Trust said: “While we understand public concern about the coronavirus, we do not encourage the degradation of the giant Cerne Abbas.
“Such an action can damage this fragile site, whether by someone who physically attaches it to it or gives the impression of having done so, because it can encourage others.
“The giant is protected both as an ancient heritage monument and as a site of particular scientific interest because of its large chalk meadow which is home to wild flowers, butterflies and other wildlife.”