This is what low-powered spell-casters use instead of actually turning people into toads. It's much easier to cast than Polymorph Other and the results are much more entertaining.

Most give the target some kind of hint as to what animal they're supposed to be before casting. This is not necessary, but usually prevents the victim from picking something they'd like.

Affliction [20] 
    Disadvantage [+25%] 
        Bestial [-10] 
        Severe Delusion ("I'm an animal") [-15] 
    Malediction (As Regular Spell) [+100%] 
    Based on Activation Roll [+5%] 
    Magical [-10%] 
    Spell Components [-20%] 
        Must say "animal" in Latin 
        Must gesture with hands 
Level 2 [25] 
    Increase Malediction to Speed/Range table [+50%] 
Level 3 [30] 
    Add Area Effect (2 yard radius) [+50%] 
Level 4-7 [35/40/45/50] 
    Increase Area Effect by 1 step [+50%]