To get this easter egg you must do like me:

1- Walk on the first level

2- When the Hill song stoppes go back

3- If you heard this sound like "Bup" just wait

4- If toad comes you will touch you (And have a jumpscare)

5-Wait the black screen for 4 seconds

6- And you will find this funny easter egg

Extra: You can click on the 2 characters (Toad the bup guy (From Nintendo) and Telephone the dutchie (From Theinodog) and that's it)