- "Much like the teenagers in "Twilight", the Vampsters are a combination of vampires and hamsters who have tremendous intellect, agility and cheek-storage capacity."
- ―The Troop official site's description of the Vampster
Vampsters are part-vampire, part-hamster monsters.
A trio of Vampsters called the Scaph Brothers appeared in Lakewood and attended Lakewood High. When Troop International realize they are Vampsters, Jake is able to go undercover and successfully befriend them. The Vampsters, planning to make Jake one of them, temporarily turn Jake into a Vampster.
Eventually, the Vampsters take Jake to their lair to permanently make him a Vampster. Hayley and Felix arrive there, but Jake and the Vampsters easily capture them. However, just as the Vampsters are about to permanently turn Jake, he turns on them and releases Hayley and Felix.
While Jake, Hayley and Felix are fighting the Vampsters, Jake turns up the temperature in the lair, weakening the Vampsters. Jake then destroys the Vampsters' power source, causing the Vampsters to die and turn to ash, and Jake to return to normal.
Vampsters resemble ordinary humans, except they have blurry eyes and large, yellow, hamster-like buckteeth.
Vampsters can control humans' minds, devour humans, and have 40 times a human's cheek capacity. They also possess superhuman strength and speed.
Ordinary humans can temporarily gain the powers and physical characteristics of Vampsters by consuming a Vampster drink, and if these humans drink human blood from a Vampster power source, they will permanently become a Vampster. Vampsters also have a power source in their lair which they rely on.
Like hamsters, heat greatly weakens Vampsters (with the apparently exception of humans who have been temporarily turned). Also, if a Vampster group's power source is destroyed, any permanently turned Vampsters in the group will die and turn to ash, and any temporarily turned Vampsters in the group will return to human. And you can tell there a vampster by their front teeth