In a new or existing conversation, enter a new message, then select the text you want to format or animate.
Do one of the following:
Choose Format near the top of your screen.
Control-click the selected text.
Select your preferred formatting (bold, italic, underline, or strikethrough) or animated effect (Big, Small, Shake, Nod, Explode, Ripple, Bloom, or Jitter).
To send your message with the format or animation, press Return on your keyboard.