A serial sex offender dressed up as comic book hero Spider-Man to scare emergency workers at the north’s biggest hospital.

James Grant also frightened waiting relatives at the casualty department at Raigmore in Inverness by striking poses in his red and blue suit.

The 36-year-old also crept up behind an ambulance technician who had a heart patient in the back of her vehicle and surprised her with a “boo”, before again adopting the familiar Spider-Man crouch.

The incidents happened on March 21, 22 and 23.

Yesterday, Grant was found guilty of breach of the pace and jailed for six months by Sheriff Gordon Fleetwood.

The sheriff told balding, slightly built, Grant: “Emergency workers have a hard enough job to do without having to deal with idiots like you.”

Grant had been remanded in custody for the past three weeks because of his criminal record, which included eight sex offences

He was jailed at the High Court in Perth in July 2014 for a serious sex assault.

Inverness Sheriff Court was told yesterday that after his Spider-Man antics he was caught by the armed police unit which was patrolling the area at the time.

He was handed over to other police officers who completed the arrest.

Grant, of 17 Ballifeary Lane, Inverness, had been cornered near a hospital building, but refused to remove his mask to reveal his identity.

Grant’s first appearance as Spider-Man was on March 21 when 49-year-old A&E receptionist Elizabeth Mackintosh was on duty.

She told the court that she thought it was “weird” when the costumed intruder walked in to the waiting area.

She said: “He was only there briefly and just posed with his arms outstretched and his palms out.

“He came back the next night and did the same pose. I didn’t like it, it made me uneasy and I contacted security.

“It was not an appropriate place for someone with a mask on, even although it was a Spider-Man costume.”

Her 57 year old colleague Catriona Douglas said in her evidence during Grant’s trial: “I was concerned about walking alone back to my car in the car park in case he was still around.

“It would frighten me if I came across a masked man at midnight.”

Ambulance technician Caroline Hafiz said Grant came up unexpectedly beside her and said “boo” before walking backwards to sit on a bench.

The mercy worker said: “I had a cardiac patient in the ambulance at the time.

“It was not the appropriate place to do something like that. He then went up to the back door and waved his hands towards my colleague and the patient.

“Then two security guards turned up and he ran off.”

The security staff caught up with Grant, who refused to remove his mask and threatened them.

The costume was produced as evidence in court and all the witnesses identified it.

Grant had denied behaving in a threatening and abusive manner on various occasions at Raigmore Hospital between March 21-23 which was likely to cause fear and alarm by repeatedly attending the hospital in full Spider-Man outfit and mask, approaching a paramedic transferring a patient from an ambulance, refusing to remove the mask and uttering threats of violence.