What term refers to a person who flatters others for self-serving reasons?

The term that refers to a person who flatters others for self-serving reasons is "toady." This word characterizes someone who acts obsequiously to gain favor or advantage from those in power or authority. A toady is often seen as insincere, as their flattery is motivated by personal gain rather than genuine admiration or respect.

In contrast, altruist describes someone who is selflessly concerned for the well-being of others, which is the opposite of self-serving behavior. A critic is someone who evaluates or expresses judgments about someone’s work, often highlighting flaws, rather than flattering them. An adversary is an opponent or enemy, which doesn't align with the concept of providing flattery or praise for personal benefit. Thus, "toady" is the correct choice as it captures the essence of self-serving flattery accurately.