Texting Chameleon
Similar to a social chameleon, a texting chameleon is someone who may change how they talk or behave in certain online environments/group chats.
For example, a texting chameleon may adopt different slang that they normally wouldn't use outside of that particular circle of people.
chameleon text
to look into someone's outbox after taking their phone so that you can copy the way they text, then text people pretending to be them for various purposes.
Claire chameleon texted Jen using her boyfriend's phone to find out if he was secretly cheating with her last night.