There seems to be quite a few variations of the Hudson’s Mud Bugger fly that have appeared, and there’s probably no end to the fun stuff you could do with it.
Here are a few variations:
Tier: Gregg Martin.
Notes: I use predominately a scud type hook size 6, but some also the M3366 or equiv. I try to match the tail to the hackle, either sili-legs or spanflex, sometimes centipede or tarantula legs. I like staight up tan for carp, but only recently came upon good hackle so only have a few tied up.
If any other tiers have other variations, send a pic or a link, and I’ll post them here.