The phrase "show your teeth" is often used metaphorically to mean standing up for oneself or displaying aggression. There are several synonyms that capture this same sentiment. One option is "bare your teeth," which means to open one's mouth and show their teeth, as animals do during a display of aggression. Another option is "flex your muscles," which expresses a similar idea of demonstrating strength or power. "Defend yourself" is another related phrase, implying the need to protect oneself from harm or attack. Finally, "stand your ground" suggests a firm and unwavering stance, ready to face any challenge that may come.