Gary Al****, 28, attacked Violet Mullen when her crying interrupted his fun on an Xbox.

The horrific assault caused "catastrophic" internal injuries, including cracked ribs and brain damage.

The attack happened under the nose of the toddler's 22-year-old mother Claire Flanagan.

But she turned a blind eye because she was desperate to keep her boyfriend Al****, Manchester Crown Court was told.

Flanagan has been jailed for five years after being cleared of murder but found guilty of causing or allowing the death.

Al**** was told he must serve a minimum of 21 years behind bars.

The court heard how the toddler had suffered at least three separate assaults in the weeks before her death.

A post-mortem examination found evidence of more than 35 separate injuries on her face and body, including bruises, rib fractures and brain damage.

Al****, who weighs more than 13 stone and has a conviction for an assault on a previous partner, attacked Violet while he was alone with the baby.

Senior investigating officer Vinnie Chadwick described the "horrendous act" as "unnecessary and cruel".

"Gary Al**** was a selfish, bullying man who took away the life of an innocent child who he had the responsibility to care for," he said.

Tessa Chapman, Sky's north of England correspondent, said medical evidence suggested Al**** had stamped on Violet.

"Little Violet Mullen did not stand a chance when his anger got the better of him," she said.

"A post-mortem found bruises all over her body. She had 35 separate injuries and she had damage to her brain, cracked ribs and internal injuries.

"There were also marks they think were pinch marks."

She added: "They think that Gary Al**** had hit her and possibly stamped on her and probably shook her as well."

Flanagan had denied witnessing any abuse, claiming she "trusted" her now ex-lover.    source: http://uk.news.yahoo.com/5/20101118/tuk-man-killed-toddler-while-playing-xbo-45dbed5.html