When online you can taunt people by pressing Start and the D-pad. Three of the taunts are the same for all the characters in almost the same way. However the fourth taunt is different.

Basic character #1 (pointed ears): Humping
Basic character #2 (big helmet): Bow
Basic character #3: Butt slap
Stranger: Holds out his arm
Soldier: Claps
NEVEC: Stands straight as if in the army
Yuri: Kneels as if praying