Some ideas

Here are my ideas! (Although you think they suck ._.)
Waste land - 5% of spawning.

Mushy dirt - step on it a few times it breaks

Waste barrels - when you break it, it explodes with waste groping on the floor

Waste - step on it you get an effect (damage speed jump boost etc.)

Corrupt crystal (used for morphing recipes)

Corrupt ore (dig it up and use it, or use a brush and find a random ore!)

Corrupt potion (corrupt ore + bottle) (gives you death or 500 points)

Morphing device - (corrupt crystal + ???) equip it and the next animal you kill you get it's powers! (Ex: kill a bunny, grow one block small, slower but you jump higher, still has name tag)

Poison water - found in waste land get it with buckets jump in it you get damage.

Sleeping waste barrel - boss (1000 health, -2 health per hit, -4 health per critical) when it dies it blows up with goop you get 2 items:

Waste key: opens up chests that could have ____????

Wash cloth: click on it twice in a row (to confirm) basically wraps up the region and you get the regular world!