Swashbuckler

[Tetrasodium]

If you've got a druid in the party (either moon or land but moon will have edge w/ beast forms over conjure spells), assassin can use the poisoner's kit to milk wildshape & summoned critters CR1 giant spider has a 2d8 dc12 save for half poison, CR1 giant toad 1d10 no save poison, CR3 giant scorpion 4d10 dc12 save for half. there might be higher level conjurable critters w/ better poisons too, but cr3 is where wildshape ends for moon druids (cr1 land)