▁various ▁reasons . ▁ ▁This ▁is ▁a ▁list ▁of ▁demon et ised ▁co ins : ▁ ▁Other ▁co ins ▁ ▁M ule ▁co ins ▁N umer ous ▁m ule ▁co ins ▁have ▁been ▁accident ally ▁mint ed , ▁at ▁least ▁two ▁of ▁which ▁have ▁ended ▁up ▁in ▁circul ation . ▁ ▁The ▁first ▁instance ▁occurred ▁in ▁ 1 9 6 7 , ▁when ▁the ▁two ▁cent ▁coin ▁was ▁accident ally ▁mint ed ▁with ▁the ▁ob verse ▁of ▁the ▁Bah am ian ▁five ▁cent ▁coin . ▁ ▁Sub sequ ent ▁examples ▁include ▁a ▁New ▁Zealand ▁ 1 9 8 1 ▁ 5 c ▁ob verse ▁mu led ▁with ▁a ▁Canadian ▁ 1 0 c ▁reverse ▁and ▁a ▁ 1 9 8 5 ▁ 5 0 c ▁ob verse ▁mu led ▁with ▁a ▁Canadian ▁$ 1 , ▁both ▁of ▁which ▁are ▁extremely ▁rare . ▁ ▁Another ▁example ▁occurred ▁in ▁ 2 0 0 0 , ▁with ▁ten ▁known ▁instances ▁of ▁the ▁comm emor ative ▁$ 5 ▁coin ▁found ▁in ▁un cir cul ated ▁sets . ▁This ▁coin ▁had ▁the ▁pied ▁c orm or ant ▁on ▁the ▁reverse ▁side , ▁as ▁did ▁the ▁other ▁$ 5 ▁co ins ▁of ▁the ▁year , ▁however ▁the ▁ob verse ▁was ▁from ▁Sol omon ▁Islands . ▁ ▁Though ▁not ▁techn ically ▁a ▁m ule , ▁a ▁mix - up ▁of ▁a ▁different ▁kind ▁arose ▁in ▁ 1 9 7 5 ▁when ▁some ▁N Z ▁ 2 0 c ▁co ins ▁were ▁accident ally ▁struck ▁on ▁scal loped ▁bl anks ▁intended