Previous Versions can be found here.
A good card if used correctly, Whimsalot is essentially the upgraded version of Whimsun, much like it is in Undertale (though less so since its change in Beta 53.1).
Whimsalot will give +1/+1 to a random monster in your hand. It repeats this multiple times, equal to the number of ally monsters it has. As such, this effect will trigger 1-4 times and functions like the buffing method of Space Cooler with the targeting of Undyne.
HOWEVER, it's currently bugged and will not give the initial buff. This means the effect will fail if it's played on its own and can only trigger by counting the other monsters on your board, so up to 3 times.