Bot that sends a random cat pic if you ping it. Needs kotlin and khttp and jda as dependencies.

CatBot.kt

import net.dv8tion.jda.core.JDABuilder
import net.dv8tion.jda.core.events.GuildMessageReceivedEvent
import khttp.get
import org.json.JSONObject

fun main(args: Array<String>) {
    JDABuilder("bot token").addEventListener(event -> {
        if (event is GuildMessageReceivedEvent && event.guild.selfMember in event.message.mentionedMembers) {
            val response = get("https://api.thecatapi.com/v1/images/search", headers = mapOf("x-api-key" to "key"))
            val cat = (response.jsonArray[0] as JSONObject).getString("url")
            event.channel.sendMessage(cat).queue()
        }
    }).build()
}