Possible Clues:

• Like Betty Boop
• Sounds as if it might be rust that gives this such a beastly look, perhaps
• Looks beastly, sounds salty
• Perhaps the beast looked at you and was so salty, by the sound of it
• Looked at last as if it might sound salty
• Sounds as if 16 across might give one a beastly look
• Looked beastly like a salt, by the sound of it