Nisha Rani, 22, made the toddler cry after she knocked him onto the floor with the toy, Coventry Magistrates Court heard.
She also pushed another young boy off a play mat as he woke up from a nap, telling the other children: 'Shh, this will be funny.'
Her behaviour was only reported after a work experience student witnessed her bullying the children and told her tutor, who called the police.
Ms Rani was suspended from her role at the privately-run nursery in Coventry and was eventually sacked, but denies the allegations, telling the court:
'I really enjoyed working with the children, the allegations have come as a shock to me.'
She was bailed and returns to court next month for sentencing.
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