(オタマモン（X抗体） Otamamon (X-Antibody))
|Cards||(Ja:) Sx-57, Dα-474|
Otamamon X is an Amphibian Digimon and carrier of the X-Antibody. Since its body has become even larger, its vocals have become louder, and the effects of its Special Move "Lullaby Bubble" have strengthened. It is said that because of a certain Mutant-type Mega Digimon, it looked forward to a promising future with its round body and was gifted the gorgeous crown "Prince no Osagari" (プリンスのオサガリ? lit. "Prince's Hand-me-down") and it became difficult to be attacked by the enemy due to its majestic appearance. Furthermore, it also taught Otamamon its Signature Move "Smiley Headbutt".
- Lullaby Bubble: Sends the opponent into an eternal slumber.
- Smiley Headbutt: Headbutts the enemy without breaking its smile, but its face still cramps up and its power is weak.
Otamamon X is an altered version of Otamamon that enhances its amphibian traits. It gains a crown on its head and bracelets on its wrists. Its body has also expanded and it has lost its hind limbs while its tail has become more tadpole-like though is still supported by rays.
- Otamamon (X-Antibody) (オタマモン（X抗体）)
Official romanization given by the Digimon Reference Book and used in the franchise. Some media modify the "(X-Antibody)" by removing the parentheses, shortening it to "X", or leaving it out entirely.
- Otamamon X (オタマモンX)
Name used in Digimon Collectors.