incarnation of selfishness; lump of avarice
A strong, often derogatory expression for a person who seems to be nothing but greed or selfish desire. Used to criticize someone's character as being entirely driven by personal gain.
He is a person who is the very incarnation of greed.
That politician is a lump of avarice and doesn't think about the people at all.
強欲 is a noun/adjective meaning 'avarice' or 'greedy', describing the trait itself, whereas 欲の塊 personifies that trait as a concrete mass.
Standard kanji spelling; 塊 is the common character for 'lump/mass'.
Alternate spelling using 固まり; less common but still seen.
Compound of 欲 (よく, 'desire, greed') + の (possessive particle) + 塊/固まり (かたまり, 'lump, mass'). Literally 'a lump of greed', used metaphorically to describe a person consumed by selfish desires.