An exclamation symbol in a square speech bubble. 

Speech Bubble With An Exclamation Mark

Two rounded speech bubbles: one with two exclamation signs and one with a simple heart shape.

Speech Bubbles With Heart And Exclamation Points

A speech bubble with an exclamation mark.

A round speech bubble with an exclamation mark.

An exclamation triangle and two speech bubbles with three dots and a question mark next to an exclamation point together.

A speech bubble with an exclamation mark in it.

A round speech bubble with an exclamation point inside it.