X-digimon are species of Digimon mutated by a vaccine. Originally injected to gain immunization from the X-program, a termination program made to eliminate Digimon, many Digimon become more powerful than their original counterparts. They are often differentiated by their "X" suffix, though some Digimon are natural carriers of this vaccine and don't have an "original", unaltered form. Those who have the X-antibody tend to have similar markings, often having the letter X or an X-like marking placed upon their bodies.
Species
Natural X-Digimon
Created ("vaccined") X-Digimon
Agumon and Gabumon lines
Lopmon and Terriermon lines
Links
https://digimon.fandom.com/wiki/X-Antibody
https://wikimon.net/X-Antibody
See also