31 October 2015 Last updated at 19:12 GMT
A group of dogs got into the spirit of the celebration at Stormont Estate on Saturday afternoon.
Claire Graham reported for BBC Newsline.

The 17-year-old was found in the graveyard of All Saints Church in Didcot, Oxfordshire, in December 2013.
She had been killed by ex-boyfriend Ben Blakeley and hidden in his uncle's grave. He was jailed for life in 2014.
The event, at the Wheatsheaf pub in Didcot, is raising money for a planned charity in her name.
Jayden's mother, Samantha Shrewsbury, said: "A man killed a child who was pregnant and had her whole life in front of her.
"I should have been babysitting last night while she went out and let her hair down, but that's never going to happen.
"I've bought gifts that she'll never receive."
She described the event, which started at 12:00 BST, as a "celebration" of Jayden's life.
"It's also to thank the Didcot people for taking her into their hearts like they have," she added.
Of the planned Jayden's Gift charity, Ms Shrewsbury said: "We want to raise awareness about domestic violence in general but also amongst teenagers."
Eventually, she hopes to provide a safe house for teenage victims of domestic violence.
"I know we can never stop it, but I hope we can make a little dent in her [Jayden's] name," she said.
A bench in memory of Jayden was unveiled in the the churchyard where her body was found in August.
In April, a memorial garden was opened on donated land near the church.
Blakeley, 23, from Reading, was convicted of murder on 24 July 2014 at Oxford Crown Court and was sentenced to life imprisonment with a minimum term of 20 years.
It is common practice for people to get dressed up for Halloween but what about our four-legged friends?
[NEXT_CONCEPT]
A memorial party for murdered teenager Jayden Parkinson is being held on what would have been her 19th birthday.