Press the following buttons to choose the same wrestlers in Excite Series or Elimination Match:
In World Championship Mode, after you've used up the 3 continues, wait until the words "Game Over" are on the screen, hold Button 2 and press Down, Left 3 times, Up 5 times, Right 4 times. If done right, you'll get 3 more continues.
At the Super Tournament number of players select screen, hold Button 2 and press Up 5 times, Right 7 times, Down 3 times and Left 6 times. If done right, the 4 hidden wrestlers will also participate in the tournament.
To fight against the hidden Bosses, complete "World Championship Series" in either the Singles or Tag team division while under "Pro Mode". Once all the selectable wrestlers have been defeated, a special series of "Lumber Jack" matches will start with the hidden Bosses as your newest opponents.