"It was abominable. Disgusting. Someone is going to be killed if something isn't done about this sort of behaviour."
Avocado Trust spokesperson Jodi Betts, who helped organise the event, said every effort had been made to tailor the day for smaller children, but Saturday's problems were part of a much bigger picture than the Santa parade.
"It's a mentality I don't understand," she said.
"It's something the whole community has to address. It's not just a one-off Christmas carnival day thing, but the parade seems to have become an occasion when some young people let loose."
The day had not started well, with "scuffles" between groups of young people at Kaitaia College and in The Warehouse car park even before the main street was closed for the parade. Teenage girls seemed to be the worst offenders; it was certainly a female teenager who hit Santa with an egg.
Parade organisers had asked businesses not to sell merchandise that might be used as missiles, and most had been very supportive, but a couple had seen the chance to make a profit.
"I'm not sure who's responsible for this, apart from the teenagers themselves and their parents," Ms Betts added.
"Street Maytz were there to keep an eye on things but it wasn't their job to intervene in fights. The police were there too, although they were pretty busy elsewhere that day."
The carnival was supposed to be a day for "little ones," but well before the parade began she saw teenagers pushing smaller children and elderly people around.
"It's no wonder many of the shops close their doors early," she said.
The trust was now looking at changing the structure of the parade, and the day in general, in a further bid to negate unacceptable behaviour, Ms Betts fearing that if "this sort of thing" was tolerated people would no longer want to be involved in what should be a special occasion.
"Some people just don't go to parade any more because of this sort of thing. A lot of kids are missing out," she said, urging anyone with any ideas as to what might be done to share them.
The parade, she added, was supposed to be for "littlies," not hulking great teenagers who couldn't control themselves. If necessary a separate occasion should be organised for that age group, so small children could enjoy their big day without witnessing intolerable behaviour or running the risk of injury.
"The Santa parade should be family-oriented," she said.
"I'm not surprised there weren't many floats. Who would want to go to the trouble of being involved in something like that? These people ruined it for everyone."