Was the Basilisk Asleep?

This was accomplished by using Parseltongue to put the creature into a deep sleep that prevented it from ageing, similar to suspended animation. Their mortal weakness was the crowing of a rooster. Basilisks fed off vertebrate animals, but it is unknown how much they ate at one time.

Was the Basilisk an animatronic?

The main Basilisk puppet was an animatronic, mechanized by Phil Ashton and Malcolm Evans. Its eyes were already gouged out, as the shots of the Basilisk before Fawkes's attack were all planned to be digital.

Is the Basilisk deaf?

When attacking, it scans for faces, especially eyes. This means looking at a Basilisk is fatal. It's completely deaf, but has a strong sense of smell. They used to roam the surface, but disappeared a long time ago when they relocated to Hollow Earth.