Toddlers and planes

What would you take for a toddler on a plane? Jamie will be two and three months when we go. I have some ideas (the normal colouring, stickers, etc) but wondered what people thought. While they're selling stocking fillers I thought it might be a good idea to get some. We've got two 12 hour plus flights (although overnight so hoping he'll sleep) and then a few internal flights of a couple of hours and a 12 hour train journey (although again overnight

Bumps did a trip to Australia not to long ago with her girls, I wonder if she could help?!
I would say maybe a DVD player so he can watch films, maybe cars or trains if he likes them?
Sorry I'm not much help