Trapper is so named because it exploits a typographic design mechanism known as ink traps purely for graphic effect.
Ink traps are a device used by type designers to create significantly higher legibility under adverse printing conditions, especially when the intended use of the type is to be printed at small sizes on mediocre substrate.
For Trapper the ink trap is overused for exaggerated visual effect. This gives the Round version a playful twisted balloons look while the Sharp has a stern mechanical default effect.
Trapper is a versatile font family of 8 fonts - sharp and round variations.