slippery as an eel

Translations
скользкий как угорь
The con artist was as slippery as an eel, making it hard for the police to catch him.
Аферист был скользким как угорь, из-за чего полиции было трудно поймать его.
Definitions
Very difficult to catch, hold, or pin down, either physically or metaphorically; often used to describe someone who is elusive, evasive, or hard to get a clear answer from.