tortoise (n.)

• alligator
• crocodile
• crocodilian
• dawdler
• dinosaur
• drone
• gator
• goldbrick
• goof-off
• laggard
• lie-abed
• lingerer
• lizard
• loiterer
• plodder
• procrastinator
• reptile
• reptilian
• saurian
• sleepyhead
• slowpoke
• slug
• sluggard
• snail
• stick-in-the-mud
• terrapin
• turtle