This V-Jump promo seems to be themed for this year’s Christmas season.
Trickstar Carobein (トリックスター・キャロベイン) [tentative name translation]
LIGHT / Level 5 / Fairy / Effect
2000 ATK / 1000 DEF
You can only use either this card name’s (1) or (2) effect per turn, and only once that turn.
(1) If you control no monsters, or all monsters you control are “Trickstar” monsters: You can Special Summon this card from your hand.
(2) From the start of the Damage Step, to before damage calculation, if a “Trickstar” monster you control battles an opponent’s monster: You can send this card from your hand to the GY; that monster you control gains ATK equal to its original ATK, until the end of this turn.
FYI, this card was briefly displayed on yu-gi-oh.jp before being taken down. So an official release date is unknown at this time.