What makes Madam Mim, Fox truly standout as a Rise of the Floodborn card is her Chasing the Rabbit ability, which requires you to banish her or return another chosen character of yours to your hand when shes played
The special foil of Ariel Singing Mermaid is an excellent choice for the art
And if you fancy a solid investment, well look no further
If the creature is already monstrous when the monstrosity ability resolves, nothing happens
For example, if you control The Ozolith ("Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.") when Zack Fair's last ability resolves, you'll put the appropriate number of each kind of counter onto both The Ozolith and the target creature
If you choose to pay two ink, she can deal damage to opposing characters after a song has been used