Mum crafts elaborate Halloween costume and dresses up as Roz from Monsters, Inc.

A mum took her Halloween costume to the next level as she dressed up as Roz from Monsters, Inc.

Sierra Larson, 30, has been competing in her office costume contest since 2016, each year raising the stakes to outdo herself.

It took Sierra an entire month to perfect her Roz costume, crafting everything from the character’s face to her signature cardigan.

To create Roz’s distinctive facial features, Sierra watched YouTube tutorials and improvised with everyday materials.