noun
mischievous child; little rascal
Wasei-eigo from 'baby gang'; used for a child who is naughty or causes trouble, often in an affectionate or humorous way. Not a literal gang member.
wasei-eigo (Japanese-coined English), from baby gang
うちの子はベビーギャングで、いつもいたずらばかりしている。
My kid is a little rascal, always up to mischief.
公園でベビーギャングたちが走り回
A bunch of mischievous kids were running around in the park.