Historical clue formulations

• Heavyweight beasts, familiarly — 2026-07-21
• Some megafauna, informally — 2025-09-14
• A group of them is called a "crash" — 2024-03-10
• Ones with good poker faces? — 2016-06-05
• Big chargers in Africa — 2014-10-21
• Charging things? — 2013-07-26
• They may be found in preserves, informally — 2013-03-29
• Massive chargers — 2012-07-14
• Zoo critters — 2012-01-19
• Thick-skinned critters — 2006-01-31
• Three-toed critters — 2004-07-30
• Safari sights — 2002-09-18
• Protected wildlife — 2001-11-23
• They're thick-skinned — 2001-08-16
• Animals with calves — 1999-10-03
• Horned zoo animals, briefly — 1995-06-20
• Zoo critters — 1994-04-14