A disturbing “Cat in the Hat” trend is spreading across social media — and police say the creepy online craze may be crossing into the real world.

Authorities in the U.S. and Canada are investigating a wave of sinister posts featuring twisted versions of the famous Dr. Seuss character, with schools, students and entire communities being named in ominous messages.

In one especially frightening incident, police say a teenage girl in British Columbia was allegedly chased through her neighborhood by someone dressed like the Cat in the Hat.

The unidentified girl was walking in West Kelowna around 9 p.m. on Aug. 24 when the costumed figure allegedly began following and chasing her, according to the Royal Canadian Mounted Police.

She managed to get home safely, but investigators have not yet identified the person behind the costume.

“Regardless of whether the individual intended the behavior as a joke, following a young person and causing them to fear for their safety is extremely concerning,” Cpl. Devon Gerrits said.

Police stressed that wearing a costume is not illegal, but chasing or following someone in a way that causes them to fear for their safety could potentially lead to criminal harassment, assault, threats or intimidation charges.

Investigators are now asking anyone with surveillance, doorbell or dashcam footage from the area around Shamrock Drive that night to come forward.

Police have not confirmed whether the alleged chase is connected to the larger online trend now alarming families across the United States.

The social media craze features edited and AI-generated images of a sinister-looking Cat in the Hat standing outside homes, lurking near schools or appearing at community landmarks.

Some anonymous accounts have gone even further, posting the names of students, teachers, schools and towns alongside threatening or ominous messages.

The posts have triggered investigations and stepped-up police patrols from California to Florida, Virginia and Texas.

In California, Baldwin Park police said officers were investigating “concerning social media posts” that referenced local schools and specifically named students and staff members.

Police warned that threats involving schools would not be brushed off as harmless pranks.

Virginia authorities also launched an investigation after a social media account posted content connected to Mechanicsville High School. Deputies increased their presence around the campus while attempting to track down whoever created the account.

In Florida, the St. Johns County Sheriff’s Office said deputies were investigating similar posts involving local schools. Authorities said they had not found evidence of a credible threat but still increased patrols around campuses as a precaution.

Texas law enforcement agencies have issued some of the strongest warnings, telling students and parents that creating, reposting or spreading threatening content could lead to serious criminal charges.

The Frio County Sheriff’s Office said some anonymous accounts were attaching lists of students, schools and communities to disturbing images and videos apparently designed to frighten the public.

Investigators determined that posts mentioning the area did not appear to pose a credible threat, but officers still boosted their presence near schools.

“Participating in, re-creating, or spreading these threatening posts is not a harmless joke,” the sheriff’s office warned.

Police in Laredo issued a similar message, warning that even someone who claims a post was only meant as a prank could end up arrested.

“A few seconds on social media can result in a police investigation, school disciplinary action, and potentially serious criminal consequences,” the department said.

The warnings are not hypothetical.

Authorities in several states have already arrested juveniles accused of taking part in the trend.

Four girls between the ages of 13 and 15 were arrested in Berwick, Louisiana, after police allegedly connected them to TikTok accounts that caused alarm among local families and schools. Three were charged with terrorizing or menacing, while another was charged with cyberbullying.

In Florida, a 12-year-old student was accused of posting a written threat to kill connected to the trend.

A 14-year-old Colorado student was also arrested after a post reportedly referenced a middle school and several homes.

Authorities in Alabama, Ohio and Kentucky have also announced arrests or possible charges involving similar social media posts.

Police across the country are now urging parents and students not to repost the disturbing images, even if they are trying to warn others.

Instead, authorities recommend taking screenshots that clearly show the account name, message, date and time, then sending the information directly to school officials or law enforcement.

Investigators say sharing the material can spread panic, make the posts go viral and make it harder for police to determine who created them in the first place.