This is Gracie. She's a very mature Candoia bibroni australis (Solomon Island Tree Boa), and she's very large for her species. They're extremely rare in private collections and it's a real shame because they are such curious and social little things with all the grace of an arboreal, but none of the attitude generally associated with other arboreals.
The 'tree boa' designation is a bit of misnomer - they're just as comfortable curled-up on the ground under a log as they are in a tree, but it helps makes the distinction between their truly terrestrial Candoia counterparts.
Gracie can change her look at-will, and she can change it quite radically. Here are 4 of her modes...
Ultra-dark (iridescence shows so well when she's dark)
In-between colours (pattern stands-out nicely in this mode)
Moderate mode
'Normal' ultra-light mode (her pinks and oranges really show nicely in this phase, but the iridescence is replaced with a *much* more satin-look finish - it's something you have to see to believe)
TODD 25 Years of Commitment and Responsibility in Private Herpetoculture