This is book two of the J.H. Brennan’s GrailQuest series, The Den of Dragons (1984 UK, 1986 US). Les Edwards painted the cover, John Higgins did the interiors. Love that stone golem, he seems very solid.

Same set up as the previous book. You are pulled into King Arthur’s time and have to save the kingdom, this time from a dragon. Maybe because that is such standard fantasy fare, this one never did it for me in comparison to the increasingly weird adventures the series gets up to.