"Ba-Da-Dum-Ching" is the onomatopoeia sound effect for what I believe is called a "rimshot".
Apparently, there is some debate over the use/meaning of that word,
but as I understand it, and as I had typed it out in my previous comment it goes like this:
A "rimshot" being 3 short drum beats and a cymbal chime at the end.
Used at the end of a one-liner, punchline, or a pun.
The latter being what I applied to your pic here for the word: "Toad-ally".
There is another sound effect used in the same situation...but kind of for an opposite meaning:
Dunno if I typed it out correctly or even what it may be called,
but this sound is usually played by a trumpet (or perhaps any other type of horn),
and is used if said one-liner, punchline, or a pun is considered to be lousy/lame or failed.