Zerimon

Extremely rare Digimon born in pairs from a single Digi-Egg. Why Zerimon and Conomon are the only Digimon that can be born as twins is currently unknown. Even more confusingly, sometimes instead of being born with a twin of the same type, one Zerimon and one Conomon will hatch from the same Digi-Egg. Zerimon, with its single horn, tends to be highly energetic, while three-horned Conomon is generally more subdued. Also, unlike other Slime Digimon, the horn on Zerimon’s head is surprisingly tough. Like other In-Training Digimon, Zerimon spits Acid Bubbles to threaten its enemies.