Moving on from Nothics and Ogres.
Here's a question, or two, because I don't really want to do the math. More as a fun thought experiment rather than anything, but it'd make for an epic story later if I actually went through the trouble to do this in a game session.
The ochre jelly is immune to slashing and lightning damage.
However, it does split in two when subjected to said damage types, into two jellies with half the hit points, rounded down. Also, it's one size category smaller.
So a large 45 hp jelly slashed is split into two medium sized jellies with 22 hp each.
1st question: How small can a jelly get?