Does animal here mean 4a person with a particular interest or aptitude in the Merriam-Webster?
Mr. Black recalled that Mr. DiCaprio dug up obscure film footage of a young Hoover giving speeches and read through transcripts of his Congressional testimony. “I had gone with a more redacted version of those, leaving out some of the more flowery, Hoovery language,” Mr. Black said. “Hoover liked to weave a lot of allusions of slimy, slippery animals into his speeches at that time. Leo loved it. He said, ‘Come on, we’ve got to use this stuff.’ ”