Spunge and Zynth was wrong, whoops, misremembered them.

Thwok is an onomatopoeia, aka a word that is basically the sound of something. Look at its page's notes, it describes it better

• Thwok's name is derived from the onomatopoeia of the same name for plucking a string (pizzicato).

The note above was taken directly from Thwok's note section

I guess you can count Thwok as a word

Also Teeter-Tauter is a real word I think

It is, but not spelled the same (teeter totter)

Also, why is this in Theories & Ideas

Ohhh I always thought it was spelled like how the monster is spelled

It makes more sense imo

Oh oh and Riff

People always need to remember how many monsters sound like their name is just a word, but it is spelled differently. Spunge, Zynth, and Teeter-Tauter are just a few examples.

Pluckbill technically counts, as it’s name is literally two otherwise unaltered words put together

Toe Jammer (2 words but who cares), Maw, Riff, Gob,