Crossword puzzle clue "a type of his work"

Opus ___ (Catholic teaching also called "the Work, work work work work")

Psychology pioneer known for his work in classical conditioning (and for his dogs): 2 wds.

He named a minor character in his most famous work Vivian Darkbloom, an anagram of his name

A TYPE OF HIS WORK

Work, work, work

Work, work, work

Type and type and type

Baseball player who hit his first home run at age 19 (Mariners, 1995) and another on his 40th birthday (Yankees, 2015): 2 wds.