The basilisk is described as a reptilian monster whose gaze can turn creatures to stone.
Basilisks usually live in deserts, in small colonies of 3-6, though they are sometimes encountered singly. However, they can be found in any climate, especially the underdark. Their lairs are little more than shallow caves or burrows in the ground, usually marked by victims of their petrifying gaze. It is possible to raise one as a guard animal, provided one has the wherewithal to do so.
A basilisk looks like a giant, six (sometimes eight)-legged lizard. The creatures aren't very intelligent, and therefore always neutral in alignment, and usually grow to around six feet long (excluding the tail) though there are also giant examples up to 30 feet in length.
This animated creature has no nodes so you can resize it to be as big or small as you like.