To get more in depth about what each term means...
Minimal: There is no significant mutation to the subject's general size.
Putty: There is significant twisting or 'melting' of the subject's form. Their flesh can take particularly strange or wrinkly shapes.
Globus: The mutation is primarily centered on the head.
Monomutated: The mutation is primarily centered on one specific area, often the neck or a limb.
Rooty: Mutation has occured in such a way as to obscure limbs and immobilize - but notably, some mutants actually develop mutated systems that root them to the ground and cause them to absorb some degree of nutrition from earth minerals and microbes. As such, some rooty subjects cannot be removed from their spot without killing them.
Worm: A very common mutation type where the torso, and only the torso, stretches out significantly. 'True' worms are mostly even in their stretching, whereas variant worms have some sort of blobby protrusions on their torso.
Spindly: Mutation has resulted in the stretching out of most/all limbs and possibly also the torso/neck. Many of these are quadrupedal.
Beastlike: Similar to spindly mutants, but their mutations focus on the upper body, giving them an animalistic appearance and significant bulk.
Lopsided: Mutation has occurred in an uneven way across the body, causing balance issues that frequently result in tripedalism.
Thoratic: Mutation is almost entirely focused on the upper body, giving them significant upper body strength.
Gigantism: Mutation occurred mostly evenly through the body. Subject has retained their ability to move bipedally due to their increased leg strength. A relatively "balanced" taxonomic class.
Extreme: A rare case of a mutant gaining new body parts, particularly a mouth or orifice where it "shouldn't" be or a new limb, due to their mutation.