Hermetic transformation spells are a double edged sword in Ars Magica, and this spell highlighted the point that reoccurs whenever I get excited about a thematic effect. Against a normal animal or human a transformed Magus is very powerful, especially if the spell has been designed to have an even more grandiose result.
However Magical Resistence completely blocks the transformed subject from attacking. This works in movies and such as they don’t have a concept of MR. In an Ars game Jafar would be very intimidating to a street rat but a complete triviality to an Order of Hermes magus. Yep I’m mixing it up but the point holds. I’d love a way for transformations to allow physical combat against wizards – such is life though.
Regardless, here is the transformation spell Jafar uses in Aladdin written up as a hermetic spell.
Transformation of the Giant Cobra
Muto Corpus / Animal 30, R: Personal, D: Sun, T: Individual
Jafar’s signature spell transforms the caster into a gigantic cobra, equivalent of a size +7 creature. The spell may be ended prematurely by dropping a cobra fang held while the spell is in effect.
(Base 10, +2 Size, +2 Sun)
A contentious part of the spell might be the size increase. My rationale is that a transformation effect can shift into any creature of size +1 or less, so when designing a spell the size of the cobra could already be large. The additional magnitudes then add on top of the large cobra, shifting the size upward by 3 tanks for each magnitude. A size 4 cobra didn’t feel big enough when I re-watched that bit of the movie, so I went to the limit of the next magnitude.
YSMV. Check out more new and custom spells for Ars Magica in my ever growing Grimoire.