Goat

The Goat is a hollow-horned, bearded mammal, originally of mountainous areas. Although it hasn't been seen in many episodes thus far, it played a major part in Walk Like An Egyptian - Part 2's challenge.

Total Drama Island
In Hook, Line and Screamer, after Owen fell off the edge of The Cliff, the goat made a cameo, being hit by Owen. Other than that, the goat made no other appearances in Total Drama Island.

Total Drama Action
The goat was not seen in Total Drama Action, although Gwen mentioned that she had a petting job at the zoo and she had to clean up after the goats in Riot on Set. In the same episode, Duncan, while acting, mentions a goat his character had in their youth.

Total Drama World Tour
The goat was first seen in Walk Like An Egyptian - Part 1, as a prize for Team Chris Is Really Really Really Really Hot. The goat appears to be quite aggressive, because as soon as Chris introduced it, it charged towards Tyler and knocked him out.

In Walk Like An Egyptian - Part 2, Team Chris Is Really Really Really Really Hot has no trouble using the goat to travel across the dessert. All the members ride it and it moves willingly, leading them to the Nile River which they must cross.