LFO {no that's not flatulence}
Yoshimi has a slightly odd characteristic with these. The depth control actually goes to 200%.
If you have a sinewave shape, it doubles the LFO frequency in exactly the same way as a fullwave rectifer does to ordinary AC, at the same time the
shape of the modulation is changed in an interesting way - especially if you just go to 150%
If it's a saw wave, it just doubles the frequency but with varying amplitude and mark-space ratio. A ramp becomes a sort of glitchy saw, and a square is a sort of glitch with a reducing square component as you increase amplitude.
I haven't put a 'scope on the other shapes