O heavy deed!

Claudius thinks aloud: that would’ve been me! Now I’ll take the blame for this for letting Hamlet run about freely in this mad condition.

4.2

Hamlet calls Rosencrantz a sponge:

ROSENCRANTZ Take you me for a sponge, my lord?
HAMLET Ay, sir; that soaks up the King’s countenance,/ his rewards, his authorities. But such officers do the/ King best service in the end. He keeps them, like an/ ape, in the corner of his jaw; first mouth’d,/ to be last swallowed. When he needs what you have/ glean’d, it is but squeezing you and, sponge, you/ shall be dry again.

Sounds crazy, huh? but:

“I’ll eat you last”: the King pays you for your spying on me, but when he’s done with you…