Various movie monsters appear during the solar eclipse event in version 1.3 and above. Some of the monsters include Dracula, Swamp Thing, Mothra, Jason, and Hellrazor.
Contributed by irh2504
The end-game armor set called "Stardust Armor" is possibly a reference to the manga Jojo's Bizarre Adventure, specifically the third story arc called Stardust Crusaders. The armor itself can summon a ghost-like guardian that will automatically defend the summoner at close range, akin to how the Stands from Jojo's Bizarre Adventure function.
Contributed by G-Haven
The item called "Flower of Fire" is a reference to the "Fire Flower" from the Super Mario Bros. franchise. Both items allow the player to shoot similarly bouncing fireballs.
Contributed by MeleeWaluigi
The Eye of Cthulhu is actually a reference to a real life writing from one of H. P. Lovecraft's short stories called the "Call of Cthulhu." It first introduced a deity called Cthulhu that is a mixture of an octopus and a dragon and has a human body.
Contributed by Oshawott90
Many of the NPC clothier's quotes are references to Tom Hanks movies, like Forrest Gump, Castaway, Apollo 13, and more. Some quotes include:
"... We have a problem! It's a blood moon out there!" Referencing Apollo 13.
"Mama always said I would make a great tailor." Referencing Forrest Gump.
"Being cursed was so lonely, so I made a friend out of leather. I named him Wilson." Referencing Cast Away.
Contributed by Arachnus
The boss Plantera's name is inspired by the band Pantera, which Creative Director Cenx says is her favourite band. Plantera drops an item called The Axe, which looks like an electric guitar often used by the band.
Contributed by Arachnus
There is a worm pet in the game that closely resembles the characters from worms.
This includes saying various lines from the series and dropping a unique tombstone upon death.
Contributed by irh2504
Several items were removed from Terraria, these include:
• Zapinator
• Scythe
• Soul Scythe
• Icemourne
• Mysterious Package
Contributed by irh2504
The Plumber's clothes are a reference to Mario. The console version colors are a reference to Mario's clothes as they appear in Donkey Kong and Mario Bros.
Contributed by noobheadz
It's possible the NPC "Party Girl" is a reference to the character "Pinkie Pie" from the TV show, "My Little Pony: Friendship is Magic". Her hair style, color scheme, general demeanor and dialogue suggests a similarity between the two. Some of her potential names are "Trixy" and "Sparkle", possibly also referencing characters from the series.
Sometimes when talking to the Wizard during the day, he may say "Someone once told me friendship is magic. That's ridiculous. You can't turn people into frogs with friendship." This is a reference to "My Little Pony: Friendship is Magic".
Contributed by Hexplosiveziggs
The tooltip "Get over here!" which appears when hovering the mouse over the Grappling Hook item, references a line that Scorpion, a recurring character in the fighting game Mortal Kombat, shouts before impaling his opponent with a grappling hook.
Contributed by pyoro64
The Giant Bat's ability to "confuse" players may be a reference to the Pokemon franchise, in which the Zubat is notorious for confusing the players' Pokemon. Some compare it to Golbat, the evolved form of Zubat, due to its size.
Contributed by AirMan121
A removed item in the game, called the Zapinator, was used by the developers in testing so they didn't have to worry about enemies. It is the strongest weapon in the game, and also resembles the Zapper, a light gun peripheral for the Nintendo Entertainment System.
Contributed by BlogDog123