Anxious Kiwi mother Stephenie Wong, who found the toy being sold on Trade Me, has called for them to be banned in New Zealand, fearing someone will be injured here.
"It is not a toy, it is a weapon potentially," Wong said in a message to the Herald.
"Its power is high... can be easily carried around, it is so dangerous."
Thomas Ladbrook, 30, a landscape gardener who has been on accident compensation since injuring his shoulder a year ago, said he started selling the 10.5cm metal "mini-crossbows" on Friday afternoon "to make a little bit of extra money".
"I started selling them the day after the Herald reported the craze," he said.
"I saw the craze and I thought I would jump on it and sell responsibly. That was my goal. I sell to adults."
Ladbrook was selling on Trade Me until the ban took effect.
"When Trade Me closed down my listing I lost $1000 in three minutes," he said.
Ladbrook is also selling the mini-crossbows on a Facebook site called Mini toothpick crossbow, with the sales pitch: "Trademe banded [sic] them get them here now $40 including shipping you get 10 high penetration arrows."
That site also includes the warning: "R18 only ask mum and dad."