A level 1 wizard cannot kill a Tarrasque as written.
Well I meant the Tarrasque as written. A level 1 wizard as written COULD have magical gear (if a level 1 wizard with wings of flight and an unlimited number of level 1 scrolls can take on T, then bad design; I havent ran the numbers but above in this thread I did specify some desiderata (EDIT: that a single PC wouldhave to acheivein order to take on the Tarrasque at level 1, or above)....