Misc: how many legs does a crab have?

Questions

The Who: What is Entwistle's famous lyrical creation, starring an arachnid?

The Who: Which member of the band played the part of "Tommy" in the movie version?

The Who's rock concert stars Elton John. Its called ________?

Their hugely successful hit off Shabooh Shoobah was called what?

Their lead singer scores most Tim Burton movies?