Yes, it is very easy to get blue w/o a leash, if you're playing a strong jungler. But it's still a good idea to leash just to make it easier for them, and to get some early ganks for your team.

Leashing is a nice way to not **** your jungler.

The only champ i can think doesnt needs a leash is nunu because of his Q and Shaco because of his jack in the box and Fiddlesticks with his drain
c ya

most people leash because they are protecting the jungler anyway. unless you like risking a 5 v 1 invade of your jungle and your jungler giving up the blue buff plus first blood.

Use you miss sooooo much cs and xp by helping the jungler with a leash right? Just be a team player and help the jungler out. You will be demanding it later so might as well help them to start with.

udyr can do blue with out a leash cause of his phoenix stance with some AD marks

you can live without a leash as any jungler, but it makes your jungling 10x better with one. a good one can give you some ridiculous timing ganks.

Never ask for a leash when I use Nunu as a jungle, and it's pretty obvious why. Some players will come even if I don't ask though.

Shaco is pretty much the only one that doesn't need a leash. If Mao starts blue, he also needs no leash. Aside from those, all junglers will need a leash to help with clear times as well as overall health.