When Paul suffered no harm from the viper on his hand, what did the islanders of Malta say?

Answer: He was a god

The islanders expected Paul to swell up or drop dead; when nothing happened, they changed their minds and said he was a god.

“The islanders were expecting him to swell up or suddenly drop dead. But after waiting a long time and seeing nothing unusual happen to him, they changed their minds and said he was a god.”— Acts 28:6 (BSB)