The Slime Beast Series by Guy N. Smith

Professor Lowson is searching the Wash for King John's lost treasure. Instead he awakes a reptilian creature buried in the mud, which seems to have arrived on this planet in a meteorite. It starts wandering around, killing and eating anybody it comes across. Lowson wants to capture it alive, his companions want to kill it before it kills anyone else. Soon the locals are involved and following a number of violent deaths and an attempted rape, there can only be a catastrophic finale.

Sequel to The Slime BeastForty years ago a hideous, scaly monster roamed the Wash, humans its victims, ripping and devouring their intestines.Gavin Royle, a young archaeologist's assistant, had finally destroyed it. Its origins were a mystery, the media claimed that it had come from outer space.Now, unbelievably, it has returned, even more dangerous than before. The Royle family are visiting the area and now Gavin must once again hunt down and kill the terrible creature known as the Slime Beast.