Mainly for my reference, but feel free to use or offer alternatives.
Back in 2nd edition there was a mutation table, for random mutations. I think there are a few weaker builds you could make and offer the mutation table on doubles.
As an example there was a fluff piece on 'Darkthunder High'. A skaven college that was placed on top of an area of warpstone, making the players highly mutable.
As however they're a college team, they'd be weaker than a pro team. So I've gone for just skaven linos with GM access and then PSA MT (Mutation Table) on doubles.
So here is my view on an updated 2nd edition random mutation table. Stay as close as possible to the original, but making it balanced. Also as I play with a client, some rules I have had to adapt to a client, even though they'd be playable on TT.
Die used is a 66:
11 Carapace: +2 AV. Notes: Originally this player would not be able to sprint/gfi. This seems to much of a nerf. I think maybe trade to "may gfi once only, +2av may take him over 10AV and upto +11AV".
12 Eyestalks: Improved eyesight. Gets catch and diving catch. Diving catch to replace +1CL.
13-14 Four Arms Gains extra arms and +1AG (why the extra ag I don't know, balance maybe).
15-16 Hideous Appearance This is a stronger version of Foul Appearance, so gains Disturbing Presence too. Basically joining the 2 skills back together.
21-22 Hopper Spring legs. So here goes Leap, Sprint, Very Long Legs as one joint skill.
23 Hypnotic Gaze As it says on the tin.
24 Leprous Flesh This was a slightly weaker version of Hideous Appearance. It could also do with a name change in this day and age, as we know more about the disease. However my take is Foul Appearance and Nurgle's Rot.
25-26 Long Arms This made the player a good catcher and intercepter. To replicate this, Catch, Pass Block, Nerves of Steel. Pass block doesn't replicate the player as such, but it does replicate the result.....he's a lethal intercepter.
31-32 Long Legs Very simple +1MA. Let's say can be added to +2 MA players (it's a mutation rather than a skill) can't take a player to MA11.
33 Mace Tail Very difficult to replicate this. So I have gone for Prehensile Tail and Mighty Blow.
34-35 Mechanical Arms Don't ask me why this was a mutation.....It's an odd one though. Gains Hail Mary and Mighty Blow.
36-41 Mechanical Eye Not so hard, player gains accurate.
42 Mechanical Legs A bit too powerful, so tamed down slightly to: gains +1MA, Leap and Kick. Still very powerful.
43 Noisome Stench Another toughy. Basically the smell affects blocking anybody in his tackle zone. So Foul Appearance and Guard.
44 Obese Negs -1 MA, -1AG may only GFI once. buffs +2 ST, Thick Skull.
45-46 Razor Sharp Claws This is pretty much modern day Mighty Blow. So you could replicate it by that or be fluffy and use the old LRB RSC (+2 on the injury roll).
51 Regeneration Seems to fit, so gains regen.
52 Scaly +1 AV.
53 Spontaneous Combustion Impossible to replicate on a client and pretty broken (but that's the MT table), so I've gone with a totally different approach. The player suffers from volatile erupting flammable boils. If he is quick enough he can pick them out and throw them like a bomb....however that's easier said than done. AG is reduced to one, gain Bomb, doesn't gain Secret Weapon if possible. If not, the ref deems him a living Secret Weapon!
54-55 Stupidity Really Stupid.
56 Tail Prehensile tail and tackle.
61 Temporal Instability Another impossible one. 2 ways to replicate this would be.......Bone Head (loses tackle zones by not being totally in this dimension) Blood Lust with no bite capacity (Was here a second ago and then just went 'ping'). Both are negs so choose which works for you.
62-63 Tentacles As this is a trait (if you like) mutation. The player gains tents and tackle.
64 3 Legs This was a bit to negative, so tamed down to: -1MA gains 'punt'. Punt = Kick and Hail Mary.
65-66 2 heads A bit of a buff on this one. Gains 2 heads and catch.
Use for weaker roster teams like all lino mutation teams. Repeated skills are wasted. Repeated rolls maybe rerolled. TV price is the price of a double, no matter what skills/traits/stats are added.