NASHUA — Downtown Nashua will host unmissable festive Halloween fun on Oct. 25 as residents and their four-legged companions gather for the annual Main Street Monster Mash Howl-o-ween.

This free, family-friendly event will feature trick-or-treating at downtown businesses, live music, costume contests for kids and pets and a few festive surprises from local performing groups.

Trick-or-treating, for children under the age of 18, will begin at 11 a.m. along Main Street.

The Humane Society for Greater Nashua is putting the “howl” in Howl-o-ween by partnering with Great American Downtown to host a Puppy Parade. The parade will begin at 11:30 a.m. on West Pearl Street. This is your opportunity to let your canine companion strut their stuff and show off their Halloween costume. Prizes will be awarded in a selection of categories such as “Most Creative” and “Best Duo (owner and pet)”. If you’d like your pup(s) to participate in the parade, please send an email to jennifer@hsfn.org.

“We are thrilled to be part of the Main Street Monster Mash Howl-o-ween. We love to be involved with our community and celebrate our beloved pets! It’s a great opportunity to explore downtown Nashua and enjoy a festive afternoon,” said Olivia Echteler, director of Community Engagement at the Humane Society for Greater Nashua.

Attendees can look forward to a special performance by the ActorSingers, one of the city’s most beloved theater groups.

The Nashua Public Library will host its own Halloween party following the 10 a.m. storytime, making it a full morning of family fun.

Attendees are encouraged to dress up, bring their pets and explore the downtown shops participating in trick-or-treating. The community can continue the fun by voting for their favorite downtown scarecrow.

The Main Street Monster Mash Howl-o-ween is free and open to the public. Attendees should plan to arrive by 11 a.m. for the start of trick-or-treating and stay for the parade, performances and a special surprise at noon. Costumes are encouraged for kids, adults and pets alike. Visitors are invited to share their photos on social media using #MonsterMashNH.