batsto - Two things. Just two things.
The foul ball.
A hit ball that goes outside the “foul lines” (the long lines running down first base and third base) is a foul ball.
With a count of no or one strike, this results in a strike.
With a count of two strikes, this results in…nothing.
Seriously. No penalty, no concession, it’s not even unofficially frowned upon. He can hack and slash and flail and thrash at pitch after pitch, for an hour if he feels like it, and he won’t get so much as a warning*.
Note that if he holds the bat in front of him (bunts), going foul with two strikes results in an out. But only if he bunts. Swinging, unlimited free cracks.
How to make him stop? Um…walk him. Or give up a hit, that also works.
The pickoff
When a runner gets on base, he will take a lead, that is, advance a small distance toward the next base to get a jump on it. When this happens, the pitcher may, instead of delivering a pitch, throw to the fielder at the base in an attempt to “pick off” the runner. If the fielder delivers the tag before the runner can return to the base, it’s a successful pickoff and the runner is out.
This fails the vast majority of the time. Forutnately, however, there is no limit to the number of times the pitcher can attempt this. He can make play catch with the fielders for an hour if he feels like it, and there’s nothing stopping him from going another hour. No penalty, no concession, it’s not even unofficially frowned upon. He is literally at greater danger of being ejected for one pitch (a single beanball can get a pitcher ejected) than 800 straight failed pickoffs.
How to make him stop? Um…get picked off. That’s about it.
If you can get used to these, NOTHING about baseball will ever bore you again. 
- I’m well aware that this is also possible in cricket, but at least that sport has a continuous bowler rotation, so it’s impossible to wear out any one bowler with such tomfoolery.