One famous tongue twister in English is:
"She sells seashells by the sea shore. The shells she sells are seashells I'm sure. And if she sells seashells by the seashore, then I sure she sells seashore shells."
Another is "say 'toy boat' ten times, fast."
Another is "Peter Piper picked a peck of pickled peppers,
A peck of pickled peppers Peter Piper picked;
But if Peter Piper picked a peck of pickled peppers,
Where are the pickled peppers Peter Piper picked?"
Warning: the joke here is that when people try to say this, they often end up saying "picked peckers," and "pecker" is a rude word.