The Case of the Visiting Vampire by Drew Stevenson, 1988.
This is the second book in the series about J. Huntley English, Monster Hunter, an extremely intelligent boy who also believes in real-life monsters and is determined to become a monster hunter so that he can find some. Along with his best friend, Raymond (who narrates the books), and Verna, a bossy girl who goes to school with Raymond, he investigates possible monsters around their small Pennsylvania town. The stories are humorous mysteries, and in a kind of Scooby-Doo fashion, there are other explanations besides monsters for the mysterious things that happen.
In this story, the Big Lake Theater in Barkley, PA, is putting on a play called The Count of Castle Dracula, and a visiting actor from Romania working at a local college is playing the part of the vampire. When Verna gets a part in the play, she becomes convinced that the actor, Bela Mezgar, is a real vampire. He behaves strangely and is never seen out during the daytime. Then, Verna overhears him talking on the phone to someone about his coffin and saying that “one heart must die so the other may live.” She tells Raymond and Huntley what she heard, and the monster hunter eagerly begins his investigation. However, a mysterious stranger also seems to be showing an unusual interest in the actor.
This book was written before the end of the Cold War, when Romania was still a communist country. Although things have changed since then, I don’t think that modern kids would have too much trouble understanding the situation. It’s a fun mystery for elementary school kids.
The book is currently available online through Internet Archive.
The Case of the Horrible Swamp Monster by Drew Stevenson, 1984.
The course of their investigation takes a strange turn when friendly Mr. Walton, who works as a janitor at the same bank where Huntley and Verna’s mothers work, is arrested for stealing money. The kids refuse to believe that he’s guilty and soon learn that there is a connection between the thefts and the mysterious monster and possibly the strange fisherman who has also been lurking around the swamp.
Gwen and Jill join a couple of other friends in forming a rock band. They want to enter a rock contest run by a local tv station. In order to enter, they have to have an original rock song, so they write one about Jill’s dog, Fletcher. They discover that Fletcher loves pizza so much that he gives a spectacular howl when they offer him some. They make Fletcher and his wonderful howl part of their act.
Fletcher is all right, but now, he suddenly hates pizza! It seems that Fletcher’s abductor fed him nothing but pizza until he started to hate it. Did someone do that on purpose to ruin their act for the contest? How would this person have even known about their act? Also, what can they do about the contest now that Fletcher is more likely to run from the sight of pizza than howl for it?
Something Queer at the Birthday Party by Elizabeth Levy, illustrated by Mordicai Gerstein, 1989.
Gwen takes her party and all the guests on a hunt across town for her missing presents, but the big clues turn out to be right back where they started, and Fletcher leads them right to what they’re looking for.
The Witch King by Maeve Henry, 1987.



#4 Mandie and the Forbidden Attic by Lois Gladys Leppard, 1985.
#3 Mandie and the Ghost Bandits by Lois Gladys Leppard, 1984.
#2 Mandie and the Cherokee Legend by Lois Gladys Leppard, 1983.
Mandie and the Secret Tunnel by Lois Gladys Leppard, 1983.