What is going on with the Extrusion? Hi so I am currently creating a Witcher Wolf School Medallion just for fun, However it's decided to do this with the last extrusion. I saved before this happened so I've being unable to fix it. 

What is this and is there any way to fix it? I appreciate any help given!


Gemma
By default your extrusion will follow the normal of your face, so if your face is slightly tilted on the Z axis it won't follow the Y axis. If you want your extrusion to follow the Y axis, you need to constraint the extrusion: press E to extrude, then Y. Also don't forget to activate the Clipping option of the Mirror modifier, it will prevent the creation of any inner faces.