the artist did a very good job of making this drawing, and it's definitely an amusing idea if it ever happened.
given how real magic is in the source material, i wouldn't be surprised if Sly was carrying a cursed artifact just long enough for it to activate, with this outcome as the result.
it's probably going to take some time for Sly to adapt to the new sets of legs and elongated body, but i can see it both being a boon and a hindrance depending on the situation.

if i walked down the street one day and saw that hanging from the roof across the street, i know exactly what i would do.

*climbs up on the roof and walks up to the last section of the taurtrain, place my hands on his back and grips his fur tightly, and then with a quick hop, heaves myself upon the taurtrain's back.*