Ah Petra, you beauty! A stunning, highly ornamental eye-catching houseplant but not for novices! Crotons like Petra love generous amount of humidity and a good deal of sunlight. But what you give, it gives back in spades. A top pick if you have the perfect spot and you're feeling the love.

South India, Sri Lanka, Malaysia, Western Pacific Islands.
Positioning + Light Needs
Bright natural light please, so a nice sun spot is good but just avoid any direct sun for too long though i can certainly take a few hours a day.
Water modestly but often to keep the soil moist, ideally using tepid filtered or rain water, during Spring / Summer months. You will need to water much less during winter. Never over water so that the plant soil is sodden, this could cause issues with your plant.
Oh yes please! I love high humidity so mist me daily with filtered or rain water, especially in the Winter months when the heating kicks in. If
 possible, improve the humidity of a room with a humidifier or place the plant on a tray of pebbles and water.
From April - September feed the plant every two weeks with a diluted fertiliser to encourage new growth and healthy looking leaves.
Every 2-3 years or so. 
Child / Pet Friendly
Oh no, I'm toxic.
Air Purifying
Oh indeed, I'm great at it too.
Look out for
Browning frond tips: Most likely cause here is dry air and lack of humidity or too low a temperature. Increase humidity levels and keep warm.
Leaves losing colour: needs more sunlight! This is the most common issue and should be simple to rectify.