Where's Waldo riddle

Question: You create your own Where's Waldo game on a piece of paper. You want your friend to find Waldo but they think you might be pulling a prank on them by not putting Waldo on the paper at all.

How can you prove to your friend that Waldo is on the paper without ruining it for them?

Question: What do you call a sad bird?

Question: What can be broken but never forgotten?

Question: What tastes better than it smells?

Question: People see through me, but none pass through without killing me. I can be anywhere, and can be seen double or single. What am I?

Question: What goes in the water black and comes out red?