Arathy Arun

Assistant Management Accountant

Arathy joined Mammoth in August 2018 as a Finance Assistant after graduating from the University of Hertfordshire with a degree in International Business. She loves travelling and experiencing other cultures; particularly their food.


Veronica Castillo

Head of Production

Ronnie joined Mammoth in 2012 as Head of Production and oversees executive production management of the Mammoth slate from development to delivery. Her productions include the Bafta nominated NW, World On Fire, Vanity Fair and Mammoth’s slate of Agatha Christie titles. Prior to joining Mammoth, Ronnie worked as a freelance co-producer and line producer on high profile film and TV titles such as The Mark of Cain, the multiple Bafta-winning Sex Traffic, It’s A Boy Girl Thing, Birdsong & Zen. She particularly enjoys the challenge of foreign filming having worked extensively across the globe and is at her happiest when she has a boarding pass in her hand! Ronnie is an active member of the Heads of Production forum and a keen advocate of diversity and inclusion across the industry.


Cheyenne Conway

Production Executive

Cheyenne joined Mammoth in 2021 as Production Executive, having previously worked as a Production Manager and Line Producer on high profile Film & TV such as Chernobyl for HBO and Sky, Louis Wain for StudioCanal and BBC Films, Hang Ups for Channel 4. She is also BAFTA nominated for Producing on Samuel-613. Cheyenne is passionate about improving inclusion and mental wellbeing in the industry.


Uju Enendu

Script Editor

Uju is a Script Editor and joined Mammoth in 2021.  She works across Mammoth’s diverse development and production slate and is currently script editing on Series VIII of Endeavour for ITV/PBS.  Uju previously supported the BBC’s TV Drama Commissioning Team after receiving a Distinction on the Playwriting & Screenwriting MA course at City, University of London.  Uju also has a background in theatre producing and dramaturgy and previously worked as a Finance Attorney at a New York law firm after receiving a JD in Law from Columbia University.


Charlotte Frings

Production & Office Manager

Charlotte started her career at the Royal Court Theatre and then became Executive Assistant to the Head of Working Title, where she assisted on productions such as Last of the Blonde Bombshells, Randall and Hopkirk (Deceased) and Ready When You Are Mr McGill. She then helped start up Big Tree Productions, whose production credits include Diverted, Abroad and cult Australian television series Woodley. She was the UK Production Coordinator of Falcón, Mammoth’s 2012 production for Sky Atlantic.


James Gandhi

Executive Producer

James joined Mammoth in 2021 as an Executive Producer, having previously worked at Studio Lambert as Head of Scripted Development where he developed a slate of projects. Prior to working at Studio Lambert, James script edited a range of projects at Mammoth, including The City & the City and Noughts + Crosses for the BBC, and Fearless and Vanity Fair for ITV.


Mark Hammond

Financial Controller

Mark joined Mammoth in September 2015 as Financial Controller and manages the head office finance function as well as working closing with the production accounts teams. Before joining Mammoth, Mark worked in a couple of finance roles at ITV having previously spent 7 years working in audit at Ernst & Young where he achieved his ACCA qualification. In his spare time, Mark enjoys spending time with his family (double act that is his young children), plays Vets football and is a keen amateur golfer.



Laura Johnston

Senior Business Affairs Manager

After studying law at Durham University, Laura was a solicitor at a leading commercial law firm before joining Mammoth in July 2016 as a Business Affairs Manager. Laura is based in the Belfast office.


Rebecca Keane

Creative Director

Rebecca has worked at Mammoth since its launch, overseeing the development slate and working across shows in production. Before joining Mammoth, Rebecca was an Executive Producer at ITV Productions, and worked as a Producer and Script Executive for United Productions and a Script Editor for Carlton TV. She studied SPS at the University of Cambridge, ultimately abandoning a PhD to work in TV.


Sarah Kelly

Business Affairs Coordinator

Sarah joined Mammoth in April 2019 and is based in the Belfast office. Sarah started her media career in the Operations Team at Stellify Media working on formats such as Who Wants To Be a Millionaire and Blind Date.


Tom Leggett

Executive Producer

Tom joined Mammoth in 2018 to spearhead a slate of new projects.

Tom began his career in film production and development. He previously worked at Universal Pictures International, Element Pictures and Film4 where he worked on features including 71’, Room, The Riot Club, Macbeth and High-Rise. He left Film4 to work in TV Drama initially at Playground Television and then later at House Productions. At both companies, Tom worked with a wide array of different writers on series, mini-series and singles for all the major UK broadcasters.


Harriet Lindsay-Stewart

Executive Assistant

Harriet joined Mammoth in January 2018. She is now Executive Assistant to Damien Timmer, Rebecca Keane and Karen Thrussell.


Preethi Mavahalli

Director of Drama

Preethi has developed and Executive Produced a slate of shows for Mammoth including most recently Noughts + Crosses for BBC One, as well as McDonald & Dodds, The City & The City and NW which was nominated for two BAFTA British Academy Television Awards. Upcoming shows include The Serpent for BBC / Netflix. Prior to joining Mammoth, Preethi worked in development at Film4, and at Film London on the micro-budget feature film scheme Microwave, where she worked across the slate of films from development through to exhibition – including the BAFTA-nominated Shifty and Ben Drew’s directorial debut Ill Manors. She also made a number of short films including a Random Act for Channel 4 directed by The Streets’ Mike Skinner.


Melanie Morris

Development Executive

Melanie joined Mammoth in January 2012, originally to provide legal and business affairs support on the company’s projects, and spent 3 years as Mammoth’s Head of Business Affairs. She now splits her time between business affairs and development.  Before training as a lawyer, Melanie worked in television production and development for a number of indies in Dublin. She read English at the University of Oxford and has a masters from Trinity College Dublin in Anglo-Irish literature.


Sherie Myers

Development Producer

Sherie joined Mammoth as Development Editor in 2019. She started her career at STV and has extensive experience across the UK’s biggest scripted indies, working for Sky, BBC, Netflix and HBO. Her latest shows include Mammoth’s latest true crime series The Serpent and the critically acclaimed I May Destroy You. She is currently running her own development slate at Mammoth with both new and established British talent.


James Penny

Managing Director

James is primarily responsible for all Mammoth’s commercial and business affairs, having joined the company in 2012. He was previously Head of Business Affairs (Drama, Comedy & Film) at Granada Television, then a partner at law firm Arthur Cox specialising in television production, financing and distribution. From 2006 he worked at Industry Media, a boutique commercial and business affairs consultancy, advising many of the UK’s leading television production companies, agencies, broadcasters and financiers. He is a member of the British Screen Forum and a director of Northern Ireland Fencing. James was a board member of Northern Ireland Screen for 10 years.


Shikira Porter

Script Editor

Shikira joined Mammoth in 2021 as a Script Editor. She started her career reading scripts as an intern at various production companies and since then she has worked on developing shows for the BBC, Netflix and Channel 4.


Joe Shrubb

Production & Development Coordinator

Joe began his career in the TV industry at the BBC as a floor runner and then a 3rd Assistant Director. After freelancing on various projects, including Endeavour series 3, he joined Mammoth’s head office as Production Assistant. Since then he has progressed through to his current role of Production & Development Coordinator. Amongst other things, Joe looks after submissions and supports the production teams working across the Mammoth slate.



Paul Testar

Co Producer

Paul is co-producer of Mammoth’s BBC/Netflix series The Serpent. In his time at Mammoth, Paul has developed and script edited many of Mammoth’s shows including The War Of The Worlds, The ABC Murders, Endeavour and NW. Paul joined Mammoth in 2014 after graduating from Trinity College Dublin with a degree in English Literature. In his spare time, Paul enjoys cycling, running, hiking, swimming and anything to do with film and theatre.



Karen Thrussell

Senior Executive Producer

Karen joined Mammoth in 2012 after two years as Executive Producer at Chorion, looking after the film, TV and stage exploitation of literary estates for writers including Agatha Christie, Georges Simenon, Enid Blyton and Raymond Chandler. She executive produced And Then There Were None, Witness for the Prosecution, Ordeal By Innocence and Poldark series 1-5 for the BBC and, most recently, The Singapore Grip for ITV. Prior to this Karen produced twenty Poirot and Marple films for ITV Studios and the two-part thriller If I Had You.


Damien Timmer

Chief Executive Officer and Founder

Damien established Mammoth in 2007, working on a wide range of dramas including Parade’s End, Poldark, NW, Noughts + Crosses and World on Fire. Prior to this he was Head of Drama for ITV Productions for five years, working on shows including Housewife 49 and Casanova. Damien worked at United Productions for three years as an Executive Producer, and before this worked at Central Films and Carlton as a producer, development executive and script editor.


Jon Williams

Chief Operating Officer

Jon joined Mammoth as Director of Production & Finance just after its inception in 2007 and has overseen all of Mammoth’s production and financial affairs since. Prior to this he was Production Executive at ITV Productions, managing productions including Agatha Christie’s Marple, William & Mary, The Last Detective and The Brief. Previously he was Finance Manager for Granada Media working across drama productions such as Prime Suspect, Sex Traffic, Cold Feet, Dr Zhivago, Island at War, Henry VIII and The Forsyte Saga. Jon cut his production teeth at United Productions, initially as a management accountant and then as production accountant on Hearts and Bones and Where the Heart Is. He is a Chartered Management Accountant.


Emma Yap

Script Editor

Emma is Script Editor at Mammoth. She previously worked as a Researcher on WORLD ON FIRE Season 2. Emma joined the media industry in 2013 after being accepted as a writer on the Royal Court Theatre’s Unheard Voices scheme. She has worked in International Sales at Bankside Films, Global Acquisitions at NBC Universal, and in Scripted Development for Bryncoed Productions. She was a mentee on Women in Film & TV’s 2020 scheme.


Helen Ziegler

Director of Television

Helen is Director of Television at Mammoth. Her recent Executive Producer credits include Peter Bowker’s BBC One epic drama, World on Fire; the latest BBC One Agatha Christie adaptations by Sarah Phelps, The Pale Horse, The ABC Murders and Ordeal by Innocence; and Russell Lewis’ critically-acclaimed prequel to Morse, Endeavour for ITV. She is currently working on World on Fire series 2, Endeavour series 8 and a variety of new developments. Helen began her career script editing on the Golden Globe-winning psychological crime drama Luther and multi-award-winning continuing drama EastEnders. Her first producer credit was From Darkness and this was followed by Endeavour series 4.