A toy company sued to protect its use of ‘Slime.’

Hawthorne-based Mattel Inc. sued its hottest competitor, Hasbro, in federal court seeking to protect what it calls its exclusive right to the name “Slime.” Mattel markets several toys employing as their main attraction a gel by that name. Mattel lawyers Ronald W. Reagin and Stephen L. King said Hasbro has since introduced “Slime Time,” a “series of fanciful animal creatures, each of which includes digital watches within its mouth.”