You can only slap in Abe's Exoddus by standing next to a Mudokon or Slig (
) by holding L2 and pressing X. If not next to a Mudokon or Slig, Abe will get angry instead, like holding L1 and pressing O did in Abe's Oddysee.
Abe's Exoddus is the two disc, more advanced edition, while Abe's Oddysee is a single disc game.