Can someone explain why I recieve this symbol in texts?

[AC Question]

Whenever I receive a text where someone sends " <3 ", I see something else. I get a little green blob with hearts for eyes, that looks kind of like the android robot. I am using a galaxy s6. Is there a way to stop this from happening, or can you explain why this is happening? Any information is appreciated, as I have searched some forums and cannot find anyone describing the same phenomenon. Thank you in advance!