The reports raised expectations of an exotic animal, perhaps a dangerous beast that had escaped from captivity.
So when animal welfare officers in the Polish city of Krakow responded to calls, they could not know what they would be faced with.
"Come and pick him up,” a local woman had reportedly said.
"But who, ma'am?” the officer replied.
The woman described the sight in more detail: “This creature!!! He's been sitting in a tree across the block for two days! People don't open windows because they're afraid it's going to enter their house.”
However, when the officers visited the street, the true cause of this panic was rather less dramatic: a croissant, wedged in the tree.
‘Not an April Fool’
The Krakow Animal Welfare Society maintained that the incident was genuine and not an April Fool.
Writing in a Facebook post, they said its officers had asked the caller whether the unidentified animal, which had been in the tree for two days, could be a bird of prey.
She replied that it looked more like a "lagun" - Polish for lagoon - before remembering the correct word "legwan", or iguana.
But when they got there they discovered, on closer inspection, that the object stuck in the lilac tree was in fact the French baked good, possibly thrown out of a window to feed birds.
The organisation did remind their followers that it’s always best to be cautious: “We note that it's always worth reporting if something concerns you.”