▁co ins ▁are ▁cert ified ▁by ▁NGC ▁with ▁the ▁following ▁names : ▁▁ ▁Bi ▁An ▁ ▁Bi ▁X i ▁ ▁Ch ao ▁F eng ▁ ▁Chi ▁W en ▁ ▁Fu ▁X i ▁( The ▁real ▁name ▁is ▁X i ▁X i ) ▁ ▁Pu ▁La o ▁ ▁Q iu ▁N iu ▁ ▁Su an ▁Ni ▁ ▁Ya ▁Z i ▁ ▁Number ▁nine ▁▁ ▁The ▁number ▁nine ▁is ▁special ▁in ▁China ▁as ▁it ▁is ▁the ▁largest ▁possible ▁single ▁digit , ▁and ▁Chinese ▁drag ons ▁are ▁frequently ▁connected ▁with ▁it . ▁For ▁example , ▁a ▁Chinese ▁drag on ▁is ▁normally ▁described ▁in ▁terms ▁of ▁nine ▁attributes ▁and ▁usually ▁has ▁ 1 1 7 ▁( 9 x 1 3 ) ▁scales ▁- ▁ 8 1 ▁( 9 x 9 ) ▁Yang ▁and ▁ 3 6 ▁( 9 x 4 ) ▁Y in . ▁This ▁is ▁also ▁why ▁there ▁are ▁nine ▁forms ▁of ▁the ▁drag on ▁and ▁there ▁are ▁ 9 ▁sons ▁of ▁the ▁drag on . ▁The ▁N ine - Drag on ▁Wall ▁is ▁a ▁spirit ▁wall ▁with ▁images ▁of ▁nine ▁different ▁drag ons , ▁and ▁is ▁found ▁in ▁imperial ▁Chinese ▁pal aces ▁and ▁gard ens . ▁Because ▁nine ▁was ▁considered ▁the ▁number ▁of ▁the ▁em peror , ▁only ▁the ▁most ▁senior ▁officials ▁were ▁allowed ▁to ▁wear ▁nine ▁drag ons ▁on ▁their ▁ro bes   — ▁and ▁then ▁only ▁with ▁the ▁ro be ▁completely ▁covered ▁with ▁sur co ats . ▁Lower - ran king ▁officials ▁had ▁eight ▁or ▁five ▁drag ons ▁on ▁their ▁ro bes ,