“Law & Order: SVU” has 21 seasons under its belt.  And even if you’ve been watching it the whole time, I bet you can’t remember all the people who’ve made guest appearances.  The website Insider.com put together a list of 30 celebrity guest stars you’ve probably forgotten, who played VILLAINS.

1.  Elizabeth Banks played a murdering porn star on Season 3.

2.  On Season 3, Henry Winkler played a man who was stealing money from his wife.  Insult to injury:  His wife was a rape victim.

3.  David Harbour from “Stranger Things” played a guy who kidnapped and assaulted young girls on Season 4.  It was his first acting credit.

4.  Innocent little “Wonder Years” kid FRED SAVAGE appeared on Season 4 as a serial rapist.  That’s a little more serious than singing out of tune.  (???)

5.  Hayden Panettiere murdered a doctor during Season 6.

6.  On Season 8, Bob Saget played a guy who implants a tracking chip in his wife, finds out she’s cheating on him, and kills her.

7.  On Season 9, Robin Williams played a sound engineer who used his expertise to cause chaos, including getting someone to commit suicide.

8.  Luke Perry played a serial rapist on Season 10.

9.  On Season 12, John Stamos played a “reproductive abuser”, a guy who gets women pregnant without their consent.  In his case, he poked holes in condoms.  But it caught up to him, because he was found dead with his chest ripped open.

10.  A pre-“Riverdale” Lili Reinhart played a teen killer on Season 13.

(Check out the rest of the list here.)