Pterodactyl

The pterodactyl will come at the T-Rex at three different levels, top, middle and bottom. The top requires the player not to jump, middle can be ducked under, and bottom can be jumped over.

Death
When the Lonely T-Rex touches a pterodactyl, it dies.

Trivia

 * Some players claim that they are birds. However, the source code says "PTERODACTYL". This isn't accurate though, as technically a pterodactyl is a member of the genus Pterodactylus and the pterosaurs in the game look more like Pteranondon.