The first trailer for HBO's The Last of Us shows off what are possibly going to be the scariest creatures prevalent in the series: Clickers. The adaptation's story will be almost identical to the Last of Us video game, taking place in a post-apocalyptic future where a fungal outbreak has spread through the population and crippled society. The series will focus on Joel and Ellie (Pedro Pascal and Bella Ramsey), an unlikely duo thrown together by circumstance who embark on a journey across the country.

The Last of Us trailer makes it clear just how faithful the series will be by adapting many of The Last of Us game's characters, locations, and creatures. The creatures include Runners, which are humans who have contracted the Cordyceps brain infection. This infection causes people to lose their higher brain functions alongside their humanity, becoming increasingly volatile and hyper-aggressive all the while being incapable of reason or logical thought. The Runners are the weakest type of infected in the game; they are humans who have only recently contracted the infection.

Related: HBO's The Last Of Us Can Perfect The Hardest Game Mechanic

Humans who have been infected for longer become Clickers. Around a year after the start of infection, people lose their sight and have facial scars as a result of fungal growth on the head and face. To compensate for their lack of sight, the infected develop echolocation, which is employed by using a clicking sound — hence their name. Clickers are some of the more terrifying creatures in the game, and among the hardest to avoid or defeat. HBO proves just how horrifying Clickers look in the Last of Us series by showcasing them in one of the final shots of the trailer.

How HBO's The Last Of Us Clickers Compare To The Games

The last of us first look clickers

The design of the Clickers shown in the first trailer for The Last of Us looks almost identical to what is found in the 2013 video game. The Clickers in HBO's adaptation have the creature's most defining visual trait: the intense fungal growth. One of the final shots of the trailer shows a clicker screaming at, presumably, Joel and Ellie. The creature has a notable lack of eyes and a horrifying fungal growth surrounding its mouth. Another comparable aspect is the Clickers' iconic sound, which can be heard in the trailer. Carrying this design over from the game is a great choice by HBO, as it shows how scary the creature can look in live-action and increases the anticipation of seeing Joel and Ellie from The Last of Us go up against the monsters.

The biggest difference between HBO's Clickers and the game design is in its tangibility. From the brief shot shown in the Last of Us trailer, it looks as if the Clickers have been created practically with minimal CGI. This shows the benefits of live-action against a video game, as the practicality of the creatures makes them even scarier than they were in the game. If this series is anything to go by, it is clear that the Clickers in HBO's adaptation will be comparable to the games in their terrifying nature. It remains to be seen just how much of a presence the Clickers will have in the adaptation, although if the faithfulness to the game from the trailer proves anything, it's that HBO's The Last of Us is only making the iconic creatures even more petrifying.