The Doctor Who series 15 teaser trailer shows an old-fashioned pug-nosed cartoon character terrifying the 1950s-styled audience by climbing out of a cinema screen. In Doctor Who Magazine 613, showrunner Russell T Davies teased the actor behind the character as an old friend of the show, guess who?!No guessing required, as the voice has been confirmed as that of actor, musicals star and presenter of The Traitors US Alan Cumming. Faithful viewers will know that Cumming appeared as a guest star during the Jodie Whittaker era, playing King James I in series 11s historical fantasy story The Witchfinders.In episode two of the new series, which is confirmed to start on BBC One and Disney+ on Saturday April 12 (with episodes available to stream on BBC iPlayer from 8am in the UK ahead of broadcast that evening) Cumming voices the character of Mr Ring-a-Ding. Hes described as a happy, funny, singalong cartoon, who lives in Sunny Town with his friend Sunshine Sally. However, in 1952, after years of repeats in cinemas across the land, Mr Ring-a-Ding suddenly looks beyond the screen and sees the real world outside, and the consequences are terrifying.Cumming joins fellow series 15 guest stars Rose Ayling-Ellis, previously of EastEnders, Ludwig, and a former Strictly Come Dancing winner who was once rumoured to be the Doctors new companion before Millie Gibson was announced. RTD teased her episode in DWM 613, writing that Rose takes it to a whole new level. She storms in with an astonishing performance of terror, anger and bravery in one of the most frightening episodes weve ever madeConfirmed last week, Australian actor Christopher Chung, best known over here for playing genius hacker and overall pillock Roddy Ho in Apple TV+ spy thriller Slow Horses, will also appear in the new episodes as a Trooper character named Cassio Palin. And weve known for a while now that The Little Mermaids Eric, aka Jonah Hauer-King, will be part of the series opener alongside Millie Gibson.Returning cast members include, of course, Ncuti Gatwa as the Doctor, Millie Gibson as Ruby Sunday, plus new companion Belind Chandra played by Varada Sethu. Theyll be joined by Anita Dobson as the mysterious Mrs Flood, Michelle Greenidge as Rubys mother Carla, Ruth Madeley as UNIT scientist Shirley Anne Bingham, Jemma Redgrave as UNIT boss Kate Lethbridge-Stewart, and Susan Twist as, presumably, tech magnate Susan Triad.Remind yourself of the teaser trailer below:Doctor Who series 15/season 2 starts on BBC One and iPlayer in the UK, and on Disney+ around the world, on Saturday April 12, 2025.