How to use a variable with spawn eggs.

[Bethins]

Skript Version: 2.5.1
Minecraft: Paper 1.15.2

I want this...

on damage:
    set {_victim} to "%victim%"
    if attacker is holding Heart of the Sea named "Capture Container":
        cancel event
        if attacker has enough space for 1 %{_victim}% spawn egg named "Captured %{_victim}%":
            send "You have Captured the %{_victim}%!" to attacker
            teleport victim 100 meters below attacker
            give attacker %{_victim}% spawn egg named "Captured %{_victim}%"
            add 1 to {player.captured.%{_victim}%}
            send "You have captured %{player.captured.%{_victim}%}%!" to attacker
        else:
            send "You are out of space in your inventory!" to attacker

But it gives me errors and I can only get this to work but I'm not wanting to write code for every mob...

on damage:       
    if attacker is holding Heart of the Sea named "Capture Container":
        cancel event   
        if victim is bat:
            if attacker has enough space for 1 bat spawn egg named "Captured Bat":
                send "You have Captured the Bat!" to attacker
                teleport victim  100 meters below attacker
                give attacker bat spawn egg named "Captured Bat"
                add 1 to {player.captured.bat}
                send "You have captured %{player.captured.bat}% bats!" to attacker
            else:
                send "You are out of space in your inventory!" to attacker

The problem is with "bat spawn egg". It won't let me use a variable or even "victim" in place of "bat".

I'm sure I'm just having trouble with the syntax, its been a few years and skript has changed so much since then... I've been googling for a couple days but haven't found anything useful.

Thanks!